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Skoda OCTAVIA MK1 Service Manual

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SKODA OCTAVIA
MK1
Drive Unit
1.6 ltr./74 kW Engine, Simos 2 injection
and ignition system

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Summary of Contents for Skoda OCTAVIA MK1

  • Page 1 SKODA OCTAVIA Drive Unit 1.6 ltr./74 kW Engine, Simos 2 injection and ignition system...

  • Page 2: Table Of Contents

    1.6 LTR./74 KW ENGINE - MECHANICAL COMPONENTS............5 ............................5 ECHNICAL Engine number..........................5 Engine characteristics........................6 ENGINE ASSY,CYLINDER BLOCK,CRANKCASE...............7 ......................7 EMOVING AND NSTALLING NGINE Removing............................7 Securing the engine to the assembly stand..................17 Install.............................. 19 Tightening torques.......................... 20 Align unit mounting for engine - gearbox..................21 Assembly bracket..........................
  • Page 3 Removing and installing coolant pump..................101 Removing and installing, testing coolant thermostat..............103 Installing coolant pipe........................105 Checking the coolant system for tightness..................105 FUEL SUPPLY, GAS OPERATION..................107 ..............107 EMOVING AND INSTALLING PARTS OF THE FUEL SUPPLY SYSTEM Removing and installing fuel tank with attached parts and fuel filter..........107 Safety precautions when working on the fuel supply system............111 Rules of cleanliness........................
  • Page 4 ..................... 202 ESTING COMPONENTS AND FUNCTIONS Idle testing............................ 202 Test fuel pressure regulator and holding pressure.................203 Testing injection valves......................... 205 Inspecting the injection rate, tightness and jet formation of the injectors........208 Test fuel pump relay and control....................210 Test air mass meter -G70-......................213 Testing the intake system for tightness (unmetered air)...............216 Test voltage supply of engine control unit..................217 Test intake air temperature sender....................

  • Page 5: 1.6 Ltr./74 Kw Engine - Mechanical Components

    1.6 ltr./74 kW Engine - Mechanical Components Technical Data Engine number The engine number (“engine identification characters” and “serial number”) is located at the joint separating the engine and the gearbox. In addition, a sticker with the “engine identification characters” and “serial number” is affixed to the toothed belt guard.

  • Page 6: Engine Characteristics

    Engine characteristics Engine identification characters Manufactured 04.97 ? 08.97 ? Displacement 1,595 1,595 Power output kW at rpm 74/5600 74/5600 Torque Nm at rpm 145/3800 145/3800 Bore Ø mm 81,0 81,0 Stroke 77,4 77,4 Compression 10,3:1 10,3:1 Firing order 1-3-4-2 1-3-4-2 Fuel - RON 95 unleaded...

  • Page 7: Engine Assy,Cylinder Block,Crankcase

    Engine assy,cylinder block,crankcase Removing and Installing Engine Special tools and workshop equipment required Workshop crane (e.g. - V.A.G 1202 A-) Catch pan (e.g. -V.A.G 1306 -) Torque wrench 5 to 50 Nm (e.g. -V.A.G 1331 -) Torque wrench 40 to 200 Nm (e.g. -V.A.G 1332 -) Engine/gearbox jack (e.g.
  • Page 8 – Remove battery tray -arrows-. Open the cap of the coolant expansion – reservoir. Raise vehicle with a lift platform, pay – attention to the following points: The arms of the lift platform must be positioned under the frame side rail. WARNING Under no circumstances may the arms of the lift platform be positioned under the...
  • Page 9 Both rear jacking up points are located on both front frame side rails at the height of the marking on the sill. – Remove noise insulation panel -arrows-. Position drip tray (e.g. -V.A.G 1306-) – under the engine.
  • Page 10 Turn drain valve -arrow- at radiator to the – left and pull to the rear, fit auxiliary hose if necessary. Remove bottom coolant hose on the oil – cooler -arrow- and drain residual coolant. Remove caps for nuts and remove –...
  • Page 11 connector from air mass meter -2-. Unscrew screws -3- and -4-, remove air – filter box completely. Remove wiper arms → Electrical System – Rep.- Gr. 92; windscreen wiper and washer system Remove the cooling water tank cover. – → Body Work; Rep.-Gr. 66; Trim panels Unplug the 28-pin connector at engine –...
  • Page 12 Unhook throttle control cable – -arrows-. Vehicles fitted with a manual gearbox Press off shift rods -1- and -2- with a – screwdriver. Unbolt shift mechanism at gearbox – -arrows-. Remove the slave cylinder -arrows- and – lay aside, secure with wire, do not open the line system.
  • Page 13 Use screwdriver to press off selector – lever cable -1- at gearbox selector lever -4-, pull off securing clasp -3- at support bearing. Take off selector lever cable and place to – the side. Unbolt bracket for pressure line of power- –...
  • Page 14 Remove fuel feed line -1- and fuel feed – line -2-, to do so press latch clips at the separation point. Lines and release buttons are colour-coded. – Detach hose -3- at the ACF tank. – Detach coolant hoses: to expansion reservoir (at front coolant pipe) to thermostat housing (at bottom of radiator and at thermostat housing)
  • Page 15 Swing the the tensioning device in -the – direction of the arrow- detension the V- ribbed belt. – Remove the V-ribbed belt. Remove 2 brackets for the pressure line – of power-assisted steering (on left at gearbox and below starter). Remove the belt pulley of the vane –...
  • Page 16 – Remove pendulum support -arrows-. Remove the drive shafts from the – gearbox flanges. Lay both drive shafts to the rear and – secure with wire to the body. – Remove front exhaust pipe → Chapter. Insert engine mount -T10012- into –...

  • Page 17: Securing The Engine To The Assembly Stand

    Slacken the screws from gearbox mount – from the top -arrows-. – Carefully lower the engine with gearbox. Note Engine with gearbox must be guided carefully, in order to avoid damage and body damage. Securing the engine to the assembly stand Secure the engine with the engine and gearbox mount -MP 1-202- and on the assembly stand before performing assembly work.

  • Page 18: Install

    cover plate. Unscrew 3 nuts -arrow- from torque – converter, rotate crankshaft each time revolution for this step. After separating engine and gearbox, – secure torque converter in gearbox to prevent it dropping out. All vehicles Hook on the suspension fixture -MP 9- –...
  • Page 19 – Insert intermediate plate on sealing flange and push onto the dowel sleeves -arrows-. Vehicles fitted with a manual gearbox – Lubricate the drive shaft serration lightly with grease -G 000 100 -. – If necessary check the centering of the clutch disc. Install slave cylinder: →...

  • Page 20: Tightening Torques

    washer system. – Electrical connections and laying of cables: → Current flow diagrams and Fitting locations – Adjusting throttle control cable → Chapter. – Install the engine cover. – Check oil level before starting the engine → Octavia. Note If the battery earth strap is disconnected and connected, carry out additional operations →...

  • Page 21: Align Unit Mounting For Engine - Gearbox

    Align unit mounting for engine - gearbox WARNING Before slackening the bolts, the unit must be secured with the supporting device -MP 9-200-. Engine mounting a = 14.0 mm b = at least 10.0 mm Both bolt heads -1- must end flush with the edge -c-.
  • Page 22 Engine assembly bracket 40 Nm + 90° ( turn) → Note 25 Nm 100 Nm → Note Gearbox assembly bracket 40 Nm + 90° ( turn) → Note 25 Nm 100 Nm → Note...
  • Page 23 Hinged bracket 40 Nm +45° → Note 40 Nm +45° → Note 20 Nm + 90° ( turn) → Note Replace bolts...

  • Page 24: Enginecrankshaft Group, Pistons

    Enginecrankshaft group, pistons Disassembling and assembling engine Removing and installing V-ribbed belt Special tools and workshop equipment required Torque wrench Locating bolts -T10060- Note The following figure shows the belt drive of vehicles without air conditioning. Mark the rotation direction before removing the V-ribbed belt.
  • Page 25 Belt pulley – can be installed only in one position 45 Nm AC generator to facilitate the positioning of the AC – generator on the holder drive the threaded bushings of the retaining screws slightly backwards AC compressor – Do not open refrigerant circuit to facilitate the positioning of the AC –...
  • Page 26 – Screw with firmness 10.9: 40 Nm Combining different firmness is not – permissible Routing of ribbed V-belt on vehicles without air conditioning Routing of ribbed V-belt on vehicles with air conditioning Note Engines fitted with an AC compressor are equipped with a double ribbed V-belt.
  • Page 27 Swivel tensioning device in -direction of – arrow- to slacken the V-ribbed belt and secure with locating bolts -T10060-. Note The tensioning device can also be locked using a 3 mm hexagon wrench. – Remove the V-ribbed belt. Installing the V-ribbed belt Note Before installing the ribbed V-belt, ensure that all components (alternator, AC...

  • Page 28: Removing And Installing, Tightening The Timing Belt

    Removing and installing, tightening the timing belt Note Before removing the timing belt, mark direction of running. Reversing the rotation direction of an already used belt may destroy it. Bottom toothed belt guard unscrew to remove the vibration – dampener →...
  • Page 29 key -pos. 14- 12 - Toothed belt guard 13 - 10 Nm 14 - Woodruff key – check tightness 15 - Hall sender -G40- when bolting on, ensure base plate is – centered 16 - 10 Nm 17 - Rear timing belt guard 18 - 20 Nm 19 - Semi-automatic tensioning pulley...
  • Page 30 Fitting position of the semi-automatic tensioning pulley The angle bracket -arrow- must engage in the recess at the cylinder head. Special tools and workshop equipment required Torque wrench Counterholder -MP 1-216- Two-hole nut turner -T10020- Counterholder -MP 1-310- Supporting device - MP 9-200- Removing toothed belt Engine installed –...
  • Page 31 Rotate crankshaft to TDC cylinder 1 – -arrow- (vehicles with automatic gearbox). TDC marking on drive plate and reference mark must be aligned. Note When engine removed, position vibration damper to TDC cylinder 1 -arrows-. – Remove engine cover. Insert supporting device -MP 9-200- and –...
  • Page 32 belt. Slacken semi-automatic tensioning pulley – and take off toothed belt. – Turn crankshaft slightly back. Unbolt engine support from engine – -arrows-. Note To slacken the front bolt of the engine support, raise engine slightly with spindle of supporting device -MP 9-200-. To take off engine support, raise or lower engine, respectively with the supporting device -MP 9-200-.
  • Page 33 Bring the marking on the camshaft – sprocket in line with the marking on the rear timing belt guard -arrows-. Position crankshaft to TDC cylinder 1 – (except when engine removed) → Anchor. Fit timing belt onto the crankshaft timing –...

  • Page 34: Inspecting Semi-Automatic Tensioning Pulley

    Tighten the timing belt. Turn with – -T10020- at centering piece to the left (in direction of arrow) up to the stop. Slacken the timing belt until the notch -1- – and the pointer -2- are positioned opposite. Tighten clamping sleeve securing semi- –...
  • Page 35 Load timing belt by firmly pressing down with – thumb -arrows-. The pointer -2- must move to the side. Relieve the toothed belt again. The tensioning roller must go back again to its initial position. – (The notch -1- and the pointer -2- are again standing opposite to each other.) Note Use mirror.

  • Page 36: Removing And Installing Crankshaft

    Removing and installing crankshaft Note Repairs to the clutch: → 5 speed Manual gearbox 02K; Rep. Gr. 30; Repairing the clutch. The engine should be attached to the engine repair stand with engine holder -MP 1-202- for carrying out removal and installation work.

  • Page 37: Removing And Installing Pressure Plate

    Bearing shell Identification for ordering replacement – parts → Fig. for bearing cap without lubricating – groove do not mix up used bearing shells – (mark) 9 - 40 Nm + torque a further turn (90°) – replace 10 - Bearing caps –...
  • Page 38 16 - Gasket ring – replace 17 - Screw plug - 100 Nm 18 - Intermediate plate – inserted on sealing flange → Fig. – must be positioned on dowel sleeves do not damage/bend during assembly – work 19 - 15 Nm 20 - Rear sealing flange with gasket ring –...
  • Page 39 Gasket ring versions I Elastomer gasket ring 1 sealing lip -1-; with garter spring II PTFE gasket ring multiple sealing lips -2-; without garter spring Note Do no moisten the PTFE gasket ring with oil before inserting. The shaft must also be free from oil and grease.
  • Page 40 Marking on crankshaft bearing for ordering replacement parts The crankshaft bearing shells are factory- classified. Align the top crankshaft bearing shells according to the marking on the cylinder block (stamped letters). Note t -Arrow- points to the belt pulley. Identification of the bearing is visible without removal of the oil pan.
  • Page 41 -holes offset-. Replacing gasket ring for crankshaft -on the belt pulley side- Special tools and workshop equipment required Torque wrench Counterholder -T30004- or Counterholer -MP 1-310 - Gasket ring extractor -MP 1-226- Insertion sleeve -MP 1-314- Insertion sleeve -MP 1-315- Guide bushing -T10053/1- Pressure bushing -T10053- Removing...
  • Page 42 Oil the thread head of the gasket ring – extractor -MP 1-226-, position and forcely screw into the gasket ring as far as possible. Slacken knurled bolt and turn inner part – against the crankshaft until the gasket ring is pulled out. Install elastomer gasket ring.
  • Page 43 Install -T10053/1- guide bushing on the – crankshaft stub. Slide gasket ring over the guide bushing – onto the crankshaft stub. Press in gasket ring with pressure – bushing -T10053- up to the stop. Use the old central screw for the crankshaft timing belt sprocket for this purpose.
  • Page 44 Put the counterholder -MP 1-221- into the bore – hole on the cylinder block and screw onto the pressure plate. – Release screws for pressure plate. Note Replace screws for pressure plate. Tighten bolts to 60 Nm and torque a further –...
  • Page 45 Only insert the drive – plate using the washer with recesses -1-. Insert bolts -3- and – tighten to 30 Nm. Inspect installed dimension of drive plate – at the 3 mounting holes for the torque converter and calculate mean value. t Nominal value -a- 19.5...21.1 mm Note The measurement is made through the 3...

  • Page 46: Removing And Installing The Front Sealing Flange

    Place spacer washer – -2- between crankshaft and drive plate. Lock drive plate with spacer washer -1- – and attach new bolts -3- to 60 Nm + torque a further turn (90°). Removing and installing the front sealing flange Special tools and workshop equipment required Torque wrench 5 - 50 Nm (e.g.
  • Page 47 Remove crankshaft timing belt sprocket. – Lock toothed belt gear - crankshaft with counterholder -MP 1-310- or counterholder -T30004 -. Note When screwing on the counterholder place 2 washers between the timing belt gear and the counterholder. – Drain engine oil. –...
  • Page 48 Cut off tip of tube at the front marking (Ø – of opening approx. 3 mm). Thickness of sealant bead -arrows-: 2 to 3 Note The sealant bead must not be thicker than 3 mm otherwise excess sealant may get into the oil pan and clogg the strainer in the oil suction pipe.
  • Page 49 Note Replace central screw of toothed belt gear. Tighten central screw to 90 Nm and – torque a further turn (90°). – Installing the timing belt → Chapter.

  • Page 50: Disassembling And Assembling Piston And Conrod

    Disassembling and assembling piston and conrod Note The engine should be attached to the engine repair stand with engine holder -MP 1-202- for carrying out removal and installation work. Piston rings – Offset joint 120° use piston ring pliers for removing and –...
  • Page 51 – mark assignment to cylinder -B- Fitting position: Markings -A- must be – positioned one above the other and point to the belt pulley side 5 - 30 Nm + torque a further 90° ( turn) – replace with conrod bolt -pos. 10- –...
  • Page 52 Inspecting piston ring gap clearance Special tools, test equipment as well as aids required Feeler gauge Test sequence Push in ring at right angles to the cylinder – wall from the top through to the bottom cylinder opening, about 15 mm from the cylinder edge.
  • Page 53 Piston ring Wear limit dimensions in mm 1st Compression ring 0.06 to 0.09 0,20 2nd Compression ring 0.05 to 0.08 0,20 Oil scraper ring 0.03 to 0.06 0,15 Inspecting pistons Special tools and workshop equipment required t External micrometer 75...100 mm Test sequence Measure about 10 mm from the lower –...
  • Page 54 Different versions of conrods Cut open conrod -A- = locating face – smooth Split conrod -B- = locating face – coarse...

  • Page 55: Engine Cylinder Head, Valve Gear

    Engine cylinder head, valve gear Removing and installing cylinder head Removing and installing timing belt → Chapter. Testing compression pressure → Chapter. Note Always replace cylinder head bolts. Always replace self-locking nuts. Always replace the seals and gaskets during assembly work. When installing an exchange cylinder head with the camshaft installed, it is necessary to oil the contact surfaces between bucket tappets and the cam track after installing the head.
  • Page 56 15 Nm 20 Nm Rear timing belt guard Cylinder head after replacing fill entire system with fresh coolant removing → Chapter check for distortion → Chapter rework → Chapter installing → Chapter Cylinder head bolt replace pay attention to order for slackening →...
  • Page 57 Oil separator Gasket for cylinder head cover replace if damaged before fitting, coat surface of cylinder head cover and cylinder head surface with -D 454 300 A2- Reinforcing strip Cylinder head cover removing and installing → Chapter 10 - 10 Nm 11 - Upper part of collecting intake manifold removing and installing...

  • Page 58: Removing And Installing Upper Part Of Collecting Intake Manifold

    23 - Gasket replace 24 - Lifting eye 25 - Cylinder head gasket replace → Chapter Removing and installing upper part of collecting intake manifold Special tools and workshop equipment required Torque wrench 5 to 50 Nm (e.g. -V.A.G 1331-) Pliers for spring strap clips 2 hose clamps -MP 7-602 - Cable strap...
  • Page 59 Detach air guide hose at throttle valve – connection and at vent housing of the crankcase ventilation -arrows-. Detach vent hose -1- and unplug – connector from air mass meter -2-. Unscrew bolts -3- and -4- and remove air – filter housing.

  • Page 60: Removing And Installing Cylinder Head Cover

    Release on left and right each one screw – -arrow- of the rear intake manifold suspension. Press off upper part of collecting intake – manifold to the rear from lower part of collecting intake manifold. Note Seal the intake passages in the bottom part of the collecting intake manifold with plug (clean cloth).

  • Page 61: Removing Cylinder Head

    – Remove reinforcing strips, bracket, toothed belt guard and cylinder head cover. Install Note Replace seals if damaged. – Remove cylinder head cover, reinforcing strips, toothed belt guard and bracket. – Tighten the nuts crosswise to 10 Nm. Removing cylinder head Note All cable straps which are detached or cut open when removing, should be fitted on again in the same place when installing.
  • Page 62 Remove noise dampening in the middle – as well as on the left -arrows-. Unbolt front exhaust pipe from exhaust – manifold → Chapter. Turn drain valve -arrow- at radiator to the – left and pull to the rear, fit auxiliary hose onto connection if necessary.
  • Page 63 Remove further the bottom coolant hose – on the oil cooler -arrow- and drain residual coolant. Detach air guide hose at throttle valve – connection and at vent housing of the crankcase ventilation -arrows-. Detach vent hose -1- and unplug –...
  • Page 64 Rotate crankshaft to TDC cylinder 1 – -arrow- (vehicles with automatic gearbox). TDC marking on drive plate and reference mark must be aligned. TDC marking on drive plate and reference mark must be aligned. Note When engine removed, position vibration damper to TDC cylinder 1 -arrows-.

  • Page 65: Inspecting The Cylinder Head For Distortion

    head. Unscrew left coolant flange at cylinder – head. – Pull out coolant pipe towards the left. – Remove cylinder head cover → Chapter. Release the cylinder head bolts in the – order 1 to 10. Remove cylinder head with cylinder head –...

  • Page 66: Installing Cylinder Head

    Reworking of the cylinder head (face- – grinding) is only permissible up to minimum dimension -a-. t Minimum dimension a: 132.6 mm Note If the sealing surface is reworked, the valves should be set lower by the same amount (rework valve seat rings) otherwise the valves will strike the pistons.

  • Page 67: Testing The Compression

    Tighten the cylinder head screws in two – stages in the indicated tightening sequence as follows: – 1st Stage: 40 Nm 2nd stage: tighten further with a rigid – wrench: torque a further 180° ( turn) 2 x 90° is not permissible Note Tightening up the cylinder head bolts after doing repair work is not necessary.
  • Page 68 – Open throttle valve fully. – Test compression with compression tester (e.g. -V.A.G 1381- and/or -V.A.G 1763-). Note Use of tester: → Operating Instructions – Operate starter until the tester no longer indicates a pressure rise. Compression readings: New engine Wear limit Pressure difference between individual cylinders 1.0 to 1.3 MPa...

  • Page 69: Repairing Valve Gear

    Repairing Valve Gear Note Cylinder heads with cracks between the valve seats or between a valve seat ring and the spark plug thread may continue to be used without any reduction in life provided these are slight initial cracks which are not more than 0.3 mm wide, or cracks exist only at the first 4 turns of the spark plug thread.
  • Page 70 Lightly coat head contact surface 1 with – sealant -AMV 174 004 01- Camshaft – inspecting axial play → Fig. – removing and installing → Chapter – Slack: max. 0.05 mm Bucket tappets – do not interchange with hydraulic valve clearance –...
  • Page 71 15 - Valve do not rework, only grinding in is – permissible – Valve dimensions → Fig. inspect camshaft, axial play Special tools and workshop equipment required t Universal dial gauge holder -MP 3-447- Dial gauge Wear limit: max. 0.15 mm Perform measurement with the bucket tappets removed and the first and last bearing cap fitted.

  • Page 72: Replacing Camshaft Gasket Ring

    Valve dimensions Note Valves must not be reworked. Only grinding in is permissible. Dimension Inlet valve Exhaust valve Ø a 39,5 ± 0,15 32,9 ± 0,15 Ø b 6,92 ± 0,02 6,92 ± 0,02 91,85 91,15 α ∠° Replacing camshaft gasket ring Special tools and workshop equipment required Counterholder -MP 1-216- Gasket ring extractor -MP 1-215-...
  • Page 73 Position camshaft sprocket to TDC marking of cylinder 1 by rotating at – crankshaft. Marking on camshaft sprocket must be aligned with arrow on the toothed belt guard. Slacken tensioning pulley and take off – timing belt. – Remove camshaft sprocket. –...

  • Page 74: Removing And Installing Camshaft

    Insert guide bushing -T10071/1- on the – camshaft stub. Position gasket ring over the guide – bushing onto the camshaft stub and remove sleeve. Press in the gasket ring with pressure – bushing -T10071- and screw -T10071/2- up to the stop. Proceed as follows for both versions –...
  • Page 75 Position camshaft sprocket to TDC marking of cylinder 1 by rotating at – crankshaft. Marking on camshaft sprocket must be aligned with arrow on the toothed belt guard. Slacken tensioning pulley and take off – timing belt. Remove upper part of collecting intake –...

  • Page 76: Testing Hydraulic Bucket Tappets

    Install bearing caps – 5, 1 and 3 and also tighten to 20 Nm. Set the Woodruff key – in the camshaft. Install camshaft sprocket and tighten – to 100 Nm (use counterholder -MP 1- 216-). Installing and – tensioning toothed belt (setting timing) →...
  • Page 77 Note t Always replace bucket tappet complete (cannot be adjusted or repaired). Irregular valve noises when starting engine are normal. Lay aside removed bucket tappets with the contact surface (camshaft side) facing down onto a clean surface. After installing new bucket tappets, the engine must not be started for about 30 minutes. The hydraulic clearance compensation elements must settle (otherwise valves would strike the pistons).

  • Page 78: Replacing Valve Stem Seals

    Replacing valve stem seals Cylinder head fitted Special tools and workshop equipment required Extractor -MP 1-206- Pressure hose -MP 1-210- Valve lever -MP 1-211- Insertion tool -MP 1-212- Assembly device for valves -MP 1-213- Removing – Remove the camshaft → Chapter.

  • Page 79: Inspect Valve Guides

    Use pulling device -MP 1-206- to pull off – valve stem seals. Install To avoid damaging the new valve stem – seals insert plastic bushing -A- on the valve stem. Insert valve stem seal -B- in the insertion – tool -MP 1-212-, oil sealing lip and carefully push onto the valve guide.

  • Page 80: Replacing The Valve Guides

    Insert valve into guide. End of valve stem must – be flush with guide. – Determine valve rock. Wear limit Inlet valve Exhaust valve 1.0 mm 1.3 mm Note If the wear limit is exceeded, repeat measurement with new valves. If the wear limit is again exceeded, replace valve guide.

  • Page 81: Reworking Valve Seats

    soluble oil while doing this. – Install new valves. – Rework the valve seats → Chapter. Reworking valve seats Special tools and workshop equipment required Depth gauge/caliper gauge NAC milling cutter for reworking valve seats Grinding paste Note When carrying out repairs on engines with leaking valves, it is not sufficient to machine or replace the valve seats and valves.
  • Page 82 distance measured -a- 34.5 mm Minimum dimension 33.8 mm = Max. permissible reworking dimension 0.7 mm Note If the max. permissible reworking dimension is 0 mm, repeat measurement with a new valve. If the max. permissible reworking dimension is again 0 mm, replace cylinder head. Reworking valve seats Dimension Valve seats...
  • Page 83 Reworking valve seats with NAC milling cutter Place cylinder head on a felt base and – secure to prevent it from turning. Match diameter of guide drift to diameter – of valve guide. Valve guide Ø Guide drift in mm Inlet valve 7,0 -0,01 Exhaust valve...
  • Page 84 Grind in valve/valve seat -arrows- with – fine grinding paste until a perfect contact pattern is achieved. – Check tightness of valves. The inspection can be carried out with water colour (perfect contact pattern over entire circumference) or by filling fuel into the combustion chamber (no fuel must flow out at the valve seat).

  • Page 85: Engine Lubrication

    Engine lubrication Removing and installing parts of the lubrication system Note If considerable quantities of metal swarf or abrasion is found in the engine oil when carrying out engine repairs, carefully clean the oil galleries in order to avoid consequential damage and additionally replace the oil cooler.

  • Page 86: Disassembling And Assembling Oil Filter Holder

    Collar screw, 15 Nm Bush Chain tensioner – together with pos. 7, 8, 10 and 11 10 - Spring 11 - Washer 12 - Sprocket 13 - “O” ring – replace 14 - 15 Nm 15 - Suction line – Clean strainer if dirty 16 - Baffle...
  • Page 87 – Insert into lugs on oil cooler...

  • Page 88: Removing And Installing Oil Pan

    17 - Oil cooler ensure clearance to surrounding – components – pay attention to the notes → Chapter 18 - 25 Nm 19 - Oil filter – slacken with tensioning strap – tighten by hand pay attention to installation instructions –...
  • Page 89 Remove noise insulation panel in middle as – well as on left and right -arrows-. – Drain engine oil. – Unbolt oil pan. Note Slacken oil pan bolts at flywheel side with hinged wrench -3185- and unscrew with wrench socket -3249-.

  • Page 90: Testing Oil Pressure And Oil Pressure Switch

    Cut off nozzle tube of the silicone sealant – -D 176 404 A2 - at the front marking (Ø of nozzle approx. 3 mm). t Thickness of sealant bead: 2 to 3 mm The sealant must be run past on the inside in the area of the bolt holes -arrows-.
  • Page 91 Voltage tester (e.g. - V.A.G 1527-) Measuring tool set (e.g. -V.A.G 1594-) Current flow diagram Function of dynamic oil pressure warning system if oil pressure low The oil pressure switch is opened when pressureless and closed when the switching pressure is reached.
  • Page 92 Unscrew oil pressure switch and screw in – oil pressure tester (e.g. - V.A.G 1342-). Screw oil pressure switch -2- into the test – equipment -V.A.G 1342-. Connect brown cable -1- of tester to – earth (-). Connect voltage tester to oil pressure –...
  • Page 93 in the oil filter holder → Chapter.

  • Page 94: Engine Cooling

    Engine cooling Removing and installing parts of the cooling system Parts of the Cooling System Note When the engine is warm the cooling system is under pressure. Reduce pressure before repairs. The hose connections are secured with spring-type clips. In the event of repairs only use spring-type clips.
  • Page 95 Expansion reservoir Intake manifold 7 - Heating for throttle valve supports Heat exchanger Gearbox oil cooler – for ATF – only for vehicles with automatic gearbox Draining and filling up coolant Coolant capacity approx. 5.0 litres Special tools, test equipment as well as aids required Catch pan (e.g.
  • Page 96 Remove noise insulation in middle – -arrows- in top half of Fig. Position drip tray (e.g. -V.A.G 1306-) – under the engine. Turn the drain plug -arrow- on the radiator – to the left and draw backwards, if necessary fit auxiliary hose onto connection.
  • Page 97 In addition, detach coolant hose at – bottom of oil cooler -arrow- and allow remaining coolant to drain. Note Collect drained coolant for proper disposal. Observe the disposal instructions for coolant. Filling up Select the appropriate coolant additive from the catalogue of original parts Škoda or from the list of allowed coolant additives →...

  • Page 98: Removing And Installing Radiator

    cap with cloths and open carefully. Inspect coolant level. When engine is at operating temperature the coolant level – must be at the maximum marking, when engine is cold between the minimum and the maximum markings. Removing and installing radiator Note Always replace seals and gasket rings.
  • Page 99 Unscrew the 4 bolts -arrows- attaching – the condenser. WARNING Do not open the refrigerant circuit of the air conditioning system. Note In order to avoid damage to the condenser as well as to the refrigerant lines and hoses, ensure that the lines and hoses are not over-tensioned, kinked or bent.
  • Page 100 Unscrew 4 bolts -arrows- attaching – bottom radiator mount. For vehicles with air conditioning – Pull out radiator and condenser slightly. Take off bracket -arrow- for refrigerant – line. For all vehicles – Remove fan shroud (4 bolts). Note When removing and installing the fan shroud, ensure that the radiator fins are not damaged.

  • Page 101: Removing And Installing Coolant Pump

    Install headlight: → Electrical System, – Rep. Gr. 94; Removing and installing headlight. Electrical connections and laying of – cables: → Current Flow Diagrams, Electrical Fault Finding and Fitting Locations (Binder) Removing and installing coolant pump Special tools and workshop equipment required Torque wrench 5 to 50 Nm (e.g.
  • Page 102 Install noise insulation; -arrows- in the – lower part of the figure. – Remove V-ribbed belt → Chapter. Remove ribbed V-belt tensioning device – → Chapter. Remove top and middle toothed belt – guard → Chapter. Position crankshaft on TDC cylinder 1 –...

  • Page 103: Removing And Installing, Testing Coolant Thermostat

    additive. Attach the coolant pump. Fitting position: – Plugs in housing point downwards. Insert rear toothed belt guard, tighten – screw -1- to 20 Nm. Tighten screws -5- of coolant pump: 15 – Installing toothed belt, tensioning (setting – timing) →...

  • Page 104: Installing Coolant Pipe

    Install – Clean sealing surface for “O”-ring. Insert coolant thermostat. Fitting position: The clamp of the coolant thermostat must be – positioned vertically. – Moisten new “O”-ring with coolant additive. – Tighten bolts to 15 Nm. – Filling system with coolant →...
  • Page 105 WARNING Hot steam may escape when the compensation bottle is opened. Cover the cap with cloths and open carefully. – Open the cap of the coolant expansion reservoir. Position coolant system tester -V.A.G 1274 - – with adapter -V.A.G 1274/8- on the compensation bottle.

  • Page 106: Fuel Supply, Gas Operation

    Fuel supply, gas operation Removing and installing parts of the fuel supply system Note The hose connections are secured with screw-type clips, spring-type clips or clamp-type clips. t Always replace clamp-type clips with screw-type clips or spring-type clips. Fuel lines on the engine must always be secured with spring-type clips. The use of clamp- type or screw-type clips is not allowed.
  • Page 107 Overflow hose “O” ring replace Gravity valve to remove, unclip valve and lift up and out of the filler neck inspect valve for blockage, valve in a vertical position: open, valve tilted 45°: closed Vent line to the activated charcoal filter system →...
  • Page 108 Vent valve check → Fig. Earth connection 10 - 10 Nm 11 - Vent line 12 - Fuel tank removing and installing → Chapter 13 - Circlip removing: turn left Installing: tighten to 2 Nm 14 - Heat shield for fuel tank 15 - 20 Nm + torque a further turn (90°)

  • Page 109: Safety Precautions When Working On The Fuel Supply System

    removing and installing → Chapter Check the fuel delivery unit → Chapter. removing and installing fuel gauge sensor → Chapter q Test holding pressure: → 1.6 ltr./74 kW Motor, Simos 2 Injection and ignition system; Rep. Gr. 24; test fuel pressure regulator 24 - Union nut use wrench -MP 1-227- for removing and installing...

  • Page 110: Rules Of Cleanliness

    WARNING The fuel system is under pressure! Before opening the system lay cleaning cloths around the connection point. Reduce pressure by carefully releasing the connection point. Pay attention to the following points when removing and installing the fuel gauge sensor or the fuel delivery unit from the fuel tank: The fuel tank must not be more than full.

  • Page 111: Removing And Installing The Fuel Gauge Sender

    Unscrew union nut with wrench -MP 1- – 227 -. Pull the fuel delivery unit and the gasket – ring out of the opening of the fuel tank. Note If the delivery unit is still filled with fuel, empty it before replacing. Install Installation is performed in the reverse order.

  • Page 112: Removing And Installing The Fuel Tank

    – Unlatch and disconnect lines -3- and -4-. Raise catches -1- and -2- with a – screwdriver and remove the fuel gauge sender towards the bottom -arrow-. Install Insert the fuel gauge sender in the fuel – delivery unit guides and press upwards until they latch into position.
  • Page 113 Remove cover below fuel tank -arrows- – (if fitted). Separate return-flow line -2- (blue), feed – line -1- (black) and vent line -3- (white) at front right of fuel tank (press release button). Position engine/gearbox jack (e. g. – -V.A.G 1383 A-) below the fuel tank for supporting.

  • Page 114: Connecting Remote Control

    with the marking -R- black feed line -2- on the connection with the marking -V-. Connecting remote control Special tools and workshop equipment required t Remote control -V.A.G 1348/3A - with adapter cable -V.A.G 1348/3-2 - Procedure – Open cover of fuse holder on left side of dash panel. –...

  • Page 115: Check Fuel Flow Rate

    The fuel delivery unit must be heard to start running. (A second person is required for this purpose if the level of surrounding noise is high). If the fuel delivery unit does not run: – Switch off ignition. – Connect remote control -V.A.G 1348/3A- with adapter cable -V.A.G 1348/3-2- →...
  • Page 116 t Remote control -V.A.G 1348/3A - with adapter cable -V.A.G 1348/3-2 - Adapter -V.A.G 1318/17- Measuring vessel Test conditions Battery voltage at least 12 volts Voltage supply o.k. Fuel filter o.k. Test sequence – Switch off ignition. – Connect remote control -V.A.G 1348/- 3A with adapter cable -V.A.G 1348/3-2- →...

  • Page 117: Removing And Installing Activated Charcoal Filter System

    Compare the fuel rate with the specified – value. Minimum flow rate cm /15 seconds Voltage at fuel delivery unit when engine not running and delivery unit operating (approx. 2 volts less than battery voltage) Removing and installing activated charcoal filter system Activated charcoal filter system solenoid valve 1 -N80- Inspecting proper operation and...

  • Page 118: Repairing The Accelerator Control

    Repairing the accelerator control Throttle control cable adjust by reconnecting the fuse to the – plug-in catch → Chapter Retaining clip Accelerator pedal Spacer bush Bushing Washer Stop screw 20 Nm Adjust accelerator control Note t The throttle control cable is very sensitive to bents and must be handled very carefully when installing. Already a slight bent can lead later on to a fracture while driving.
  • Page 119 Adjust throttle control cable by reconnecting the plug-in catch at support in such a way that the throttle – valve is fully opened and the kick-down switch clicks audibly. All vehicles – Release the accelerator pedal or remove the expansion rod. –...

  • Page 120: Exhaust System

    Exhaust system Removing and installing parts of the exhaust system Note Always replace gaskets and self-locking nuts. Use a screwdriver to slacken and tighten the clamps of the heat shield. Tightening torque: 2 Nm Tunnel bridge with hole for aligning exhaust system –...
  • Page 121 – coat with hot bolt paste -G 052 112 A3- Washer 10 - Lambda probe, 50 Nm coat only thread with hot bolt paste – -G 052 112 A3-; hot bolt paste must not get into the slot of the probe body test: →...

  • Page 122: Removing And Installing Front Exhaust Pipe

    Removing and installing front exhaust pipe Special tools and workshop equipment required Torque wrench 5 to 50 Nm (e.g. -V.A.G 1331-) Removing Note Avoid a large deflection of decoupling element, max. deflection 10 °. Always replace self-locking nuts. Unbolt protective cover -arrows-, –...

  • Page 123: Removing And Installing Exhaust Manifold

    Shielding for drive shaft to cylinder block Coat with hot bolt paste -G 052 112 A3-. – Align exhaust system free of stress → Chapter. Interrogating fault memory: → 1.6 ltr./74 kW Motor, Simos 2 Injection and ignition system; – Rep.

  • Page 124: Replacing Front Or Rear Silencer

    Coat with hot bolt paste -G 052 112 A3-. – Align exhaust system free of stress → Chapter. – Install front exhaust pipe → Chapter. Replacing front or rear silencer Special tools, test equipment as well as aids required Torque wrench 5 to 50 Nm (e.g. -V.A.G 1331-) Body saw (e.g.
  • Page 125 Shop-make screw from an M10 bolt to – the dimensions stated for aligning the exhaust system. Dimension -X- = 4 mm Dimension -Y- = 25 mm Note A second person is required for aligning the exhaust system. Slacken bolted connections of clamping –...

  • Page 126: Checking The Exhaust System For Leaks

    Position clamping sleeve with a clearance – of about 5 mm to the line of the particular marking and tighten evenly in horizontal position to 40 Nm. Different markings apply depending on the gearbox version: Arrow 1 - Vehicles fitted with automatic gearbox t Arrow 2 - Vehicles with a manual gearbox The screwed connection of the clamping...

  • Page 127: 1.6 Ltr./74 Kw Engine, Simos 2 Injection And Ignition System

    1.6 ltr./74 kW Engine, Simos 2 injection and ignition system Self diagnosis, V.A.G Inspection Service Operation The control unit for the injection and ignition system is equipped with a fault memory. If malfunctions occur in the monitored sensors or components, they are stored in the fault memory with indication of the fault type.

  • Page 128: Connecting Up The Vehicle System Tester -V.a.g 1552- And Selecting The Control Unit For Engine Electronics

    04 Initiating basic setting 05 Erasing fault memory 06 Ending output 07 Coding control unit 08 Reading measured value block Only if the engine does not start (operate starter for at least 6 seconds). It must be carried out after the following operations: if the engine control unit -J220-, the throttle valve control unit -J338- or the engine are replaced.

  • Page 129: Interrogating And Erasing Fault Memory

    If there is nothing on the display: → Operating instructions of vehicle system tester Depending on the function which must be carried out: – Switch on the ignition or start the engine → Anchor. Enter address word 01 for “Engine electronics” and –...

  • Page 130: Actuator Diagnosis

    display. If no fault is stored: – Press → key. If one or several faults are stored: The stored faults are displayed in sequence. Then the following appears in the display: Vehicle system test Enter 05 for the function “Erase fault memory” and HELP –...
  • Page 131 t The ignition and injection system is locked during the final control diagnosis. With the actuator diagnosis the following parts are activated in the sequence indicated: 1.Fuel pump relay -J17- 2.Activated charcoal filter system solenoid valve 1 -N80- 3.Exhaust gas return valve -N18-, (two-way valve) →...

  • Page 132: Coding Control Unit

    actuator is activated earlier by pressing the → key. If the valve is not actuated (does not activate), check – activated charcoal filter system solenoid valve 1 -N80- → Chapter. – Press → key. Readout on display: Note Actuator diagnosis ->...
  • Page 133 For vehicles ► 04.99 Code number Gearbox Equipment 04000 Gearbox 04030 Automatic gearbox 04900 Gearbox without ABS For vehicles 05.99 ► Code number Gearbox Equipment 00001 Gearbox 00003 Automatic gearbox 00011 Gearbox 00013 Automatic gearbox 00021 Gearbox Airbag 00023 Automatic gearbox Airbag 00031 Gearbox...

  • Page 134: Self-Diagnosis I

    Self-diagnosis I Fault table Note All the possible faults which can be detected by the dash panel insert and can be displayed by -V.A.G 1552- are listed according to the fault code. If “Info in literature” appears in the display of the vehicle system tester, look for the text required in the fault table under the fault code.
  • Page 135 tolerance Control difference 00305 Fuel consumption display signal Short circuit Short circuit to positive in Check fuel consumption to positive the cable connection – display signal → Current flow between the engine diagrams and Fitting control unit and the locations. onboard computer The throttle valve positioner -V60 - is a component part of the throttle valve control unit -J338 -.
  • Page 136 Note Regarding fault code 00513: Additional signals can be generated by metal swarfs. Signals may not be generated or be too weak and therefore not be detected due to a too large distance of the sender to the sensor rotor or by a damaged sensor rotor. t The signal routing can be irregular due to a loose sensor rotor (or loose sensor).
  • Page 137 positive control unit wiring or short circuit according to current flow diagram → Current flow diagrams and Fitting locations. Short circuit -F60- defective Poor vehicle handling Check the throttle cable to earth when proceeding to – setting → 1.6 ltr./74 kW idling/overrun at Engine, Mechanics →...
  • Page 138 earth → Current flow diagrams Line interruption and Fitting locations Short circuit to earth in cable connection between - G69- and engine control unit implausible → Current flow diagrams Loose contact signal and Fitting locations -G69- defective Humidity and/or corrosion t Acceleration jerks Check plug –...
  • Page 139 start difficulties) → Chapter. -G70- defective Irregular idling or no – -G70- replace. idling in cold- running or warming- up phase Signal input in the Idling speed not Replacing engine – engine control unit within the tolerance control unit defective (engine →...
  • Page 140 up phase, transient malfunctions Earth distribution to -G42- defective Signal input in the Irregular idling or no Replacing engine – engine control unit idling in cold- control unit defective (engine running or warming- → Chapter. control unit defective) up phase 00524 Knock sensor 1 -G61- defective...
  • Page 141 Fitting locations. Short circuit to earth Earth distribution to Poor idling – Checking lambda -G39- defective control → Chapter. implausible signal Corrosion due to Increased fuel Read measured humidity in the plug consumption value block, display – connection for lambda group 001 probe heater -Z19- or →...
  • Page 142 Transition impedances t irregular idling due to humidity in the plug connection for the throttle valve control unit -J338- incorrect plug assignment 00533 Idling control upper limit value Throttle valve Poor vehicle Inspecting throttle – positioner -V60- jams handling valve control unit →...
  • Page 143 (blocked) vehicle → Chapter. handling t Fuel pressure regulator defective Test fuel pressure – regulator and holding pressure → Chapter. Fuel pump defective Test fuel pump → 1.6 – ltr./74 kW Engine, Mechanics → Rep. Gr.20. Unmetered air Check induction pipe for –...
  • Page 144 and automatic → automatic diagram → Current flow gearbox control unit gearbox → Rep. diagrams and Fitting Gr.01 locations. Short circuit to Short-circuit to earth Signal output in the Replacing engine control – earth between engine engine control unit unit →...
  • Page 145 defective unit → Chapter. If the fault 00557 is stored, the fault 00533 can also be stored as a follow-up fault. Readout on Possible cause of fault Possible Rectifying fault -V.A.G 1552- effects 00610 Ignition outlet 2 Short – see fault code “00609” see fault –...
  • Page 146 5°km/h. Readout on Possible cause of fault Possible Rectifying fault -V.A.G 1552- effects 00635 Lambda probe heating upstream of catalytic converter defective Line interruption or short- irregular Checking lambda control – circuit to positive and/or idling → Chapter. earth between engine possible Remove open circuit in wiring control unit and lambda...
  • Page 147 Clutch pedal switch -F36- defective Line interruption or short- Test the signal of the – circuit clutch pedal switch → Chapter. For vehicles 08.97 ► 00668 El. syst. voltage tml. Open circuit Line interruption/loose contact Check voltage in the wiring to the engine supply of the control –...
  • Page 148 circuit and/or for interruption → Current flow diagrams and Fitting locations. 01087 Basic setting performed implausible Conditions for the basic setting The engine control Read measured signal (adaptation of the throttle valve unit cannot learn the value block, display – control unit) not fulfilled: stop positions of the group 001 or 098...
  • Page 149 circuit to positive and/or earth between engine control unit and dash panel insert Signal input on the dash panel Replace dash panel – insert defective insert. Signal output in the engine Replacing engine – control unit defective (engine control unit control unit defective) →...
  • Page 150 defective Engine control unit Engine does Replacing engine control unit – defective not start → Chapter. Note Regarding fault code 01163: t The engine can be restarted after erasing the fault memory → Chapter. Readout on Possible cause of fault Possible effects Rectifying fault -V.A.G 1552- 01243...
  • Page 151 diagrams and Fitting locations. Short circuit to Voltage supply for -N80- possible – Check -N80- → Chapter. earth defective jerking in partial load region Output open -N80- defective Vehicle may possibly smell of fuel Signal output in the engine Replacing engine control –...
  • Page 152 Short circuit to ⇒ Cylinder 1 fault code “01249” ⇒ Cylinder 1 ⇒ Cylinder 1 fault code positive fault code “01249”. “01249” Short circuit to earth Output open 01252 Injector cyl. 4 -N33- Short circuit to ⇒ Cylinder 1 fault code “01249” ⇒ Cylinder 1 ⇒...
  • Page 153 Regarding fault code 01259: If the fault “01259” is stored, component parts can also be displayed as faulty which are supplied with voltage via the fuel pump relay → Current flow diagrams and Fitting locations. Readout on Possible cause of fault Possible effects Rectifying fault -V.A.G 1552-...
  • Page 154 Engine t Manipulation attempt control unit blocked Line interruption or short- Engine starts briefly Remove open circuit in circuit to positive and/or but then stops wiring or short circuit earth between engine immediately – according to current flow control unit and diagram →...

  • Page 155: Self - Diagnosis Ii

    Self-diagnosis II Reading measured value block Connect vehicle system tester -V.A.G 1552- and select address word 01 “Engine – electronics”. Engine idling. Readout on display: Vehicle system test Enter 08 for the function “Read measured value block” HELP – Select function XX and confirm entry with the Q key.
  • Page 156 Analysis of display group 000 → Anchor. Display group 000 (display values in decimals) Engine idling Display fields Displayed Corresponds to specified value measured value 123456 7 8 Engine speed 23 to 27 760 to 880 rpm (idling speed) Injection period 2 to 4 2 to 4.1 ms Throttle valve angle...
  • Page 157 start by a high charge current or by auxiliary equipment Transition resistance in the power supply or earth connection for engine control unit t Current consumption with ignition off greater than t Voltage regulator on generator defective Test voltage, replace –...
  • Page 158 → Chapter. Display does large unmetered air volume Eliminate cause of – not fluctuate unmetered air. Spark plug defective (lambda Test spark plugs and control on stop – t Spark plug connector defective connector. in direction rich or lean; t Holding pressure too low or too high Test fuel pressure –...
  • Page 159 filter -N80- constantly open → Chapter. Air mass meter faulty -G70- – Check -N80- → Chapter. Lambda probe heating defective or – Check -G70- → Chapter. lambda probe dirty Check lambda probe – heater → Chapter. high lambda high lambda idling learned values at –...
  • Page 160 less than 2 high fuel volume from the activated Testing solenoid valve for – charcoal filter system activated charcoal filter → Chapter. incorrect injection valves with too high fuel flow rate fitted Testing fuel injected – quantity → Chapter. t Fuel pressure regulator defective Inspect fuel pressure –...
  • Page 161 adjustment (see next page) Lambda probe voltage 0.00...1.0 → Chapt Coolant temperature 80...110 → Chapt °C Engine speed (idling speed) → Chapt Note Meaning of the digits in the 8-digit numerical block for the setting condition of the throttle valve adjustment: x x x x x x x x Meaning, if display positions = 1 Fault detected by the self-diagnosis...

  • Page 162: Reading Measured Value Block

    Engine operating condition 0100 → Anchor Driving speed 0 km/h drawn in air mass 76...164 mg/s → Chapter Idling speed → Chapter Note Meaning of the digits in the 4-digit numerical block for the engine operating condition: Meaning, if display positions = 1 Engine operating condition Trailing throttle Idling...
  • Page 163 Engine runs in idling speed Reading measured value block 4 → ← Readout on display xxx rpm xxx mg/s x.x ms x.x g/s ← Display fields Specification Analysis drawn in air mass 1.0...3.2 g/s Injection period 2...4.1 ms → Chapter drawn in air mass 76...164 mg/s →...
  • Page 164 drawn in air mass 76...164 mg/s → Chapter Idling speed → Chapter Display group 007 (idling setting): Engine runs in idling speed Reading measured value block → ← Readout on display x.x ∠° x.xx x.xx xxxx ← Display fields Specificatio Analysis Engine operating condition 0100...
  • Page 165 The measured value block 007 serves only as information. Not relevant for the fault finding in the Service Department. Display group 008 (idling speed stabilisation): Engine runs in idling speed Reading measured value block 8 → ← Readout on display xxx rpm xxx rpm xx %...

  • Page 166: Read Measured Value Block: Display Groups 011 To 099

    xxxx Adjustment status not assigned during the adaptation of the throttle valve control unit, a fault has occured (interrogate fault memory → Chapter) Throttle valve control unit dead (clock ratio = 0) 1 Adaptation aborded due to a too low battery voltage (below 8 V) 1Idling switch separated (interrogate switch) Display group 010 (lambda control and activated charcoal filter system): Engine runs in idling speed...
  • Page 167 Engine runs in idling speed Reading measured value block → ← Readout on display x.x ms x.xx ms x.xx xxxxxx ← Display fields Specification Analysis Condition of the tank vent 00000010 → Anchor valve Lambda learned value at partial load 0,90...1,15 →...
  • Page 168 Readout on Possible cause of fault Rectifying fault -V.A.G 1552 - outside tolerance Minus value: mixture too rich, Wait approx. 30 seconds until the – field lambda control leans off value stabilises. Plus value: mixture too lean, lambda Testing injection valves –...
  • Page 169 Note The measured value block 013 serves only as information. Not relevant for the fault finding in the Service Department. Display group 014 (knock control): Normal driving Reading measured value → ← Readout on display block 14 °CA °CA °CA °C 4 ←...
  • Page 170 Component parts – Attach component parts on engine loose t poor fuel quality – Change type of fuel one cylinder clearly deviates Plug connection – Testing knock sensor → Chapter from the others corroded t Engine damaged Test compression pressure: →...
  • Page 171 xxx rpm xxx mg/s °CA °C 4 ← Display fields Specificatio Analysi Ignition angle relief cylinder 4 through 0.0...12.0 → Anch knock control °KW Ignition angle relief cylinder 3 through knock 0.0...12.0 → Anch control °KW drawn in air mass Engine speed 760...6350 Note...
  • Page 172 corroded t Engine damaged Test compression pressure: → 1.6 – ltr./74 kW Engine, Mechanics → Rep. Gr.15 Component parts – Attach component parts on engine loose Display group 017 (knock control): Engine runs in idling speed Reading measured value → ←...
  • Page 173 Display group 018 (torque reduction for automatic gearbox): Engine runs in idling speed Reading measured → ← Readout on display value block 18 xxx rpm xxx mg/s x.x °CA °b. TDC ← Display fields Specificatio Analysis Ignition angle -6...14.0 °b. Ignition angle relief for the signal of the 0.0 °CA automatic gearbox control unit...
  • Page 174 Idling speed → Chapt Display group 019 (operating conditions) for vehicles 08.97 ►: Engine runs in idling speed Reading measured value → ← Readout on display block 19 xxx rpm x xxxxxxx ← Display fields Specificati Analysis Operating state of AC 00000000 →...
  • Page 175 Power-assisted steering pressure switch active 1 Air conditioning compressor on Display group 020 (operating state of lambda control, see also display group 099): Engine runs in idling speed Reading measured value → ← Readout on display block 20 xxx rpm xxx mg/s xxx °C xxxxx ←...
  • Page 176 Lambda controller switched on 1 Lambda probe operational 1 Mixture condition; display = 1: mixture too rich display = 0: mixture too lean Note Further explanation of the 8-digit number block see display group 099 → Anchor. Display group 021 (adaptation status of the throttle valve control unit; to do so see display group 098): Engine runs in idling speed Reading measured value block...
  • Page 177 valve control unit: Meaning, if display positions = 1 xxxx Adaptation status of the throttle valve control unit not assigned during the adaptation of the throttle valve control unit, a fault has occured (interrogate fault memory → Chapter) Throttle valve control unit dead (clock ratio = 0) 1 Adaptation aborded due to a too low battery voltage (below 8 V) 1Idling switch separated (interrogate switch) Display group 022 (position of camshaft to crankshaft):...
  • Page 178 signal is generated by two gaps at the sensor rotor. The trim of the hall sender at the camshaft is separated by 180°, i.e if the trim is located in the air gap of the hall sender after half a turn, the trim leaves the air gap again after the next half turn of the camshaft.
  • Page 179 Note Re display field 4: The signal output from the pressure switch (field 4) at “compr. OFF” does not give any information about the condition of the cooling medium in the air conditioning system If the fault 01013 is entered in the fault memory, 25% is always displayed in the display field 4.
  • Page 180 xxxx Adaptation status of the throttle valve control unit not assigned during the adaptation of the throttle valve control unit, a fault has occured (interrogate fault memory → Chapter) Throttle valve control unit dead (clock ratio = 0) 1 Adaptation aborded due to a too low battery voltage (below 8 V) 1Idling switch separated (interrogate switch) Note Re display field 3:...
  • Page 181 Coolant temperature 80...110 → Chapt °C Idling speed → Chapt On the points marked with “X”, a “0” or a “1” can be optionally displayed. Note Re display field 4: Meaning of the digits in the 8-digit numerical block for the condition of the lambda controller: x x x x x x x x Meaning, if display positions = 1...
  • Page 182 If the fourth bit is set to “1”, (lambda controller on stop), it can be recognized after the first bit (mixture condition) in which direction the lambda controller rests on stop. If the first bit continuously rests on “1”, the lambda controller has thus reached the stop in direction of lean but the lambda probe still measures a “fat”...

  • Page 183: Repair Simos 2 Injection System

    Repair Simos 2 injection system Safety measures WARNING The fuel system is under pressure! Place a cloth around the connecting points before releasing the hose connection or when opening the test connection (to fuel pressure measurement). Then reduce the pressure by carefully removing the hose or cap. Observe the following points to prevent injury to persons and/or damage to the injection and ignition system: t Do not touch or remove ignition leads with the engine running or at start speed.

  • Page 184: Overview Of Fitting Locations

    disconnected bar) Holding pressure after 10 minutes at least 0.15 MPa (1.5 bar) overpressure Injection valves Injection jet equal for all valves Resistance approx. 14.5 Ω (ambient temperature) → Note If the engine is warm the resistance of the injection valves increases by approx. 4...6 Ω. Overview of fitting locations For vehicles ►...

  • Page 185: For Vehicles 08.97

    4-pin connector for lambda probe and heating for lambda probe on the underside of the vehicle on right in direction of travel below a plastic cap 3-pin connector for hall sender - G40- black Hall sender -G40- below the camshaft wheel Valve for variable intake manifold changeover -N156- Intake air temperature sender -G42- Throttle valve control unit -J338-...
  • Page 186 Clutch pedal switch -F36- in footwell on the clutch pedal 3-pin connector for hall sender - G40- black Hall sender -G40- under top toothed belt guard Lambda probe -G39- with heating for lambda probe -Z19- Identification characters AEH: fitting location catalytic converter Identification characters AKL: fitting location exhaust manifold (illustration) 4-pin connector for lambda probe and heating for lambda probe...

  • Page 187: Removing And Installing Parts Of The Injection System

    at the gearbox 11 - 3-pin connector for knock sensor 1 -G61- 12 - Ignition coils (N and N128) with power output stage -N122- 13 - Engine speed sender -G28- 14 - 3-pin connector for engine speed sender -G28 - grey 15 - Knock sensor 1 -G61-...
  • Page 188 Control unit for Simos 2 -J361 - Fitting location: in plenum chamber Checking voltage supply → Chapter replace → Chapter Connector, 28 pin Insert or remove plug when the ignition is switched off unlock to remove Connector, 52 pin Insert or remove plug when the ignition is switched off unlock to remove Air intake hose To oil filler inlet...
  • Page 189 Air mass meter -G70- with intake air temperature sender - G42- up to model year 1997, the intake air temperature sender -G42- is a separate component part Testing the air mass meter → Chapter Test intake air temperature sender → Chapter Air filter disassembling and assembling →...
  • Page 190 with coolant temperature gauge sensor -G2- check → Chapter before removing, reduce pressure in cooling system if necessary 20 - Split pin check tightness 21 - O-ring replace if damaged 22 - Engine speed sender -G28- check → Chapter 23 - Gasket ring replace 24 -...
  • Page 191 Fitting location → Chapter 29 - Lambda probe -G39- 50 Nm grease the thread with “G 052 112 A3”; “G 052 112 A3” must not get into the slots of the probe body Checking lambda control → Chapter Voltage supply of the heating for lambda probe via fuel pump relay -J17- Check heating for lambda probe →...

  • Page 192: Disassembling And Assembling Top Part Of Intake Manifold

    Fitting location: stops for gasket ring at the bottom part of the intake manifold -arrows- If no stops are present at the bottom part of the intake manifold, stick the gasket ring with glue -D 000 801- and hardener - D 000 802- to the bottom part of the intake manifold.

  • Page 193: Disassembling And Assembling Fuel Distributor

    12 - Plug Disassembling and assembling fuel distributor Split pin check tightness on the injection valve – and fuel distributor Fuel distributor Injection valve (-N30-...N33) – check → Chapter O-ring – replace if damaged Fuel pressure regulator – check → Chapter Disassembling and assembling the air filter 6 Nm Air mass meter - G70- with intake air...

  • Page 194: Removing And Installing Engine Covers

    – replace if damaged 6 Nm Air filter top part Filter insert Air filter bottom part Air deflector Removing and installing engine covers Removing Lever out the plugs -1- at the points marked – with arrows and slacken the securing nuts -2- for both engine covers.

  • Page 195: Replacing Engine Control Unit

    Connect test box to connector of wiring – loom. Perform test as described in the relevant – repair sequences. WARNING To avoid damaging the electronic components, switch on the relevant measuring range before connecting the measuring cables and comply with the test conditions.

  • Page 196: Adapt The Engine Control Unit To The Electronic Immobiliser

    → Chapter Adapt the engine control unit to the throttle valve control unit - J338- → Chapter Adapt the 4AV control unit to the electronic immobiliser → Chapter Adapt the engine control unit to the electronic immobiliser Special tools and workshop equipment required Vehicle system tester -V.A.G 1552 - with cable -V.A.G 1551/3- Test condition Authorised car key available...

  • Page 197: Testing Components And Functions

    Testing components and functions Idle testing Special tools and workshop equipment required Vehicle system tester -V.A.G 1552 - with cable -V.A.G 1551/3- Test conditions Exhaust system shut. Coolant temperature minimum 80°C l Throttle valve in idling speed position → 1.6 ltr./74 kW Engine, Mechanics → Rep. Gr.20 Electrical consumers must be disconnected (the radiator cooling fan must be off during this test) AC switched off...

  • Page 198: Test Fuel Pressure Regulator And Holding Pressure

    again the fault memory → Chapter. If the idling speed is too high or too low and if there is no fault in the fault memory, perform the following inspections: l Check idling switch → Chapter → Chapter. Large quantity of unmetered air →...
  • Page 199 – Measure fuel pressure. Specified value: approx. 2.5 MPa (0.25 bar) overpressure. Detach vacuum hose from fuel pressure – regulator. The fuel pressure must rise to approx. 3 bar (3 MPa) overpressure. – Switch off ignition. Test for leaks and holding pressure while observing the pressure drop on the –...

  • Page 200: Testing Injection Valves

    Open shut-off cock at the pressure – measuring device -V.A.G 1318- (lever in direction of flow of fuel). – Start engine and run in idle. After the pressure has been built up, – switch ignition off. At the same time the return-flow hose (with blue marking) must be pressed together.
  • Page 201 Perform resistance measurement – between the contacts of the valve with multimeter. Specified value: approx. 14.5 Ω. If the engine is warm the resistance increases by approximately 4 to 6 Ω. If the nominal value is not reached, – replace the injection valve. B - Checking voltage supply Test conditions l Fuel pump relay o.k., test...

  • Page 202: Inspecting The Injection Rate, Tightness And Jet Formation Of The Injectors

    Connect voltage tester between contact – 2 of the plug and battery positive (+). – Activate the starter. Specified value: Voltage tester must flash. Note Voltage tester with low voltage consumption do not go out fully between the actuations of the engine control unit, but keep on glowing and become brighter during the actuation.
  • Page 203 Test condition Fuel pressure o.k., test → Chapter. – Detach vacuum hose from fuel pressure regulator. – Detach the fuel feed line and return line on the quick-release fittings. WARNING The fuel system is under pressure! Detach the hose which connects the solenoid valve for the activated charcoal filter with –...
  • Page 204 Initiate again an actuator diagnosis and – select the activated charcoal filter solenoid valve 1 -N80-. Note The final control diagnosis can only be initiated again after the ignition has been briefly switched off. for approx. 50 s) -V.A.G 1348/3 A-. Note l Moisten “O”...

  • Page 205: Test Fuel Pump Relay And Control

    Pay attention to correct positioning of the injectors. l Check perfect fit of the retaining clips. Test fuel pump relay and control Special tools and workshop equipment required Handheld multimeter, e.g. -V.A.G 1526 A - Voltage tester, e.g. - V.A.G 1527- Measuring tool set -V.A.G 1594 A - Test box -1598/22- Note...
  • Page 206 Disconnect fuse for fuel pump (fuse 28) at the fuse holder and connect the – voltage tester between earth and one of the two contacts of the fuse for the fuel pump → Current flow diagrams and Fitting locations. Switch on the starter motor for a short –...
  • Page 207 the relay base and earth. Specified value: approx. battery voltage each If the specified values are not reached, – eliminate line interruption → Current flow diagrams and Fitting locations. Test control Connect the voltage tester to contact 16 – of the relay base (earth control of the engine control unit) and to positive.

  • Page 208: Test Air Mass Meter -G70

    Test air mass meter -G70- Special tools and workshop equipment required Vehicle system tester V.A G 1552 with cable -V.A.G 1551/3- Handheld multimeter, e.g. -V.A.G 1526 A - Voltage tester, e.g. - V.A.G 1527- Measuring tool set -V.A.G 1594 A - Test box -V.A.G 1598/22- Check for proper operation Test conditions...
  • Page 209 07.97. Disconnect the plug from the air mass – meter -G70- and connect the multimeter between contact 3 of the plug and the engine mass. – Start engine and run in idle. Specified value: 11...15 V – Switch off ignition. If the voltage supply is o.k., check signal –...
  • Page 210 Specified value: 11...15 V – Switch off ignition. If the voltage supply is o.k., check signal – lines and earth connection → Anchor. If no voltage is present: Check the cable connection from contact 3 of the plug to fuse no. 43 for continuity –...

  • Page 211: Testing The Intake System For Tightness (Unmetered Air)

    If the lines are not found to be faulty: – Replace air mass meter -G70- with intake air temperature sender -G42- → Chapter. Testing the intake system for tightness (unmetered air) Special tools and workshop equipment required Vehicle system tester -V.A.G 1552 - with cable -V.A.G 1551/3- Testing with engine leak search spray -G 001 800 A1- Note Because of the vacuum in the intake system the leak search spray is sucked in with the unmetered air.

  • Page 212: Test Intake Air Temperature Sender

    Battery voltage at least 11 V. AC generator o.k. Connect the test box -V.A.G 1598/22 - to the wiring loom of the engine control unit – → Chapter. – Switch on ignition. – Connect multimeter for voltage measurement to bush 1 (positive via ignition) and earth. Specified value: approx.
  • Page 213 – Disconnect the plug from the intake air temperature sender. Connect multimeter to intake air – temperature sender. Temperature °C Resistance kΩ approx. °13,8 approx. °5,5 approx. °2,4 approx. °1,1 approx. °0.6 – If the specified value is not reached, replace the intake air temperature sender. If the specified value is reached, test wiring between sender plug and engine control unit –...
  • Page 214 Check the cable connection between the 2-pin plug of the intake air temperature – sender and the engine contol unit for interruption as well as for short-circuit to positive and/or to earth according to current flow diagram. Contact at 2-pin plug Test box -V.A.G 1598/22- Specified value: max.
  • Page 215 60 °C Open circuit/Short circuit to positive → Anchor Short circuit to earth approx. ambient temperature → Note → Anchor If a temperature is displayed that greatly deviates from the ambient temperature of the sender, check the sender wires for transition impedances. Continue test: –...
  • Page 216 Check the resistance between contacts 2 – + 4 of the sender. The range A shows the resistance values for the temperature range 0...50 °C, the range B the values for the temperature range 50...100 °C. Read out examples: 30 °C corresponds to a resistance of 1500...2000 Ω...

  • Page 217: Test Coolant Temperature Sender -G62

    Spray sender -arrow- with cooling spray – and while doing so observe the temperature value. The temperature value must drop. – Press → key. Enter 06 for the function “End output” – and confirm with key Q. Test coolant temperature sender -G62- Special tools and workshop equipment required Handheld multimeter, e.g.
  • Page 218 Check the resistance between contact 1 – (earth) and 3 (signal) of the sender. The range A shows the resistance values for the temperature range 0 to 50 °C, the range B the values for the temperature range 50 to 100 °C. Examples: 30 °C corresponds to a resistance of 1500 to 2000 Ω...
  • Page 219 For vehicles ► 07.97 (Pos. A) Contact at 4-pin plug Test box -V.A.G 1598/22- For vehicles 08.97 ► (Pos. B) Contact at 4-pin plug Test box -V.A.G 1598/22- If there is neither a line interruption nor a short-circuit and the coolant temperature sender –...

  • Page 220: Checking Lambda Control

    Checking lambda control The lambda probe compares the oxygen content of the air with the residual oxygen in the exhaust gas and supplies a voltage signal to the control unit. The voltage signal “mixture too rich (little residual oxygen)” is at approx. 0.7...1.0 V. The voltage signal “mixture too lean (a lot of residual oxygen)”...
  • Page 221 introduced, is influenced mainly by the following factors: Ambient temperature (summer/winter) Operating conditions after start Function of the probe heater If faults occur after cold start, it must be checked if the problem occurs before or after the control is introduced. Test vehicle under cold start conditions: Connect vehicle system tester -V.A.G 1552- and select address word 01 “Engine –...

  • Page 222: Check The Function Of The Lambda Control

    The lambda controller is activated if the lambda probe is operational. Perform a test drive and while doing so observe the – display field 4. WARNING The -V.A.G 1552- should be operated by a second person. When inserting the lambda control, the lambda probe must be operational and the lambda controller must be switched on.
  • Page 223 the display field 2 is at least 80 °C. The signal voltage of the lambda probe is displayed in the display field 3. If the probe voltage fluctuates too slowly (less than 30 – times per minute), test lambda probe heater 0000010 →...
  • Page 224 If the lambda controller stands against the stop and the display for the condition of the mixture is shown permanently on “1”, the 850/rpm 90°C lambda control has reached the control stop in direction “lean off”, +25% 00011111 however the lambda probe still detects “mixture too rich”. The following appears in the display: If the lambda controller stands against the stop and the display for the condition of the mixture is shown permanently on “0”, the lambda...

  • Page 225: Check Lambda Probe Heater

    The specified values → Chapter. Check lambda probe heater Special tools and workshop equipment required Handheld multimeter, e.g. -V.A.G 1526 A - Voltage tester, e.g. - V.A.G 1527- Measuring tool set - V.A.G 1594 A- Test box -V.A.G 1598/22- Test conditions The fuse no.

  • Page 226: Test Lambda Probe Signal Line And Lambda Probe Control Unit

    wiring loom for continuity and/or short circuit to earth, if necessary repair → Current flow diagrams and Fitting locations. Connect the test box -V.A.G 1598/22 - to – the wiring loom of the engine control unit → Chapter. Test wiring of contact 2 of plug at wiring loom (earth control of the engine control –...
  • Page 227 Use handheld multimeter to measure – voltage between the contacts 3 and 4 of the connector at the wiring loom. Specified value: 1.50...1.60°V If the specified value is not reached, – connect the test box -V.A.G 1598/22- to the wiring loom of the engine control unit →...

  • Page 228: Checking The Fuel Tank Venting

    Checking the fuel tank venting Testing activated charcoal filter system solenoid valve 1 Special tools and workshop equipment required Vehicle system tester -V.A.G 1552 - with cable -V.A.G 1551/3- Handheld multimeter, e.g. -V.A.G 1526 A - Voltage tester, e.g. - V.A.G 1527- Measuring tool set -V.A.G 1594 A - Test box -V.A.G 1598/22- Check tightness...
  • Page 229 Connect the voltage tester between – contact 1 of the plug and the engine mass. – Activate the starter. Specified value: The voltage tester must light up. If the voltage tester does not light up, – check the wiring of contact 1 to fuse for continuity, if necessary repair →...

  • Page 231: Inspecting Throttle Valve Control Unit

    Inspecting throttle valve control unit Operation The idle stabilizer is integrated into the throttle valve control unit. Throttle valve potentiometer, idling switch, throttle valve positioner and throttle valve positioner potentiometer are located in the housing opposite the control cable disc. The housing must not be opened.
  • Page 232 electronics”. Engine idling. Select 08 for the function “read measured value block” and further select display group – 002. Observe display in display field 4. Note Reading measured value block 2 -> 850/rpm 120 mg/s 0 km/s 0100 Meaning of the digits in the display field 4: Display field 4 Meaning of the display...
  • Page 233 – Repeat adaptation of the throttle valve control unit → Chapter. If the adaptation cannot be started or successfully completed, – replace the throttle valve control unit. – Perform adaptation of the throttle valve control unit → Chapter. Inspect sender for throttle valve positioner and throttle valve potentiometer –...
  • Page 234 Test wiring between the test box and the – 8-pin plug with multimeter for continuity. Test wiring with multimeter for short- – circuit relative to each other. Contact at 8-pin plug Contact to text box Remove possible line interruptions and dirt at the contacts, erase fault memory and carry –...
  • Page 235 Check idling switch Connect vehicle system tester -V.A.G 1552- and select address word 01 “Engine – electronics”. Ignition switched on. Select 08 for the function “read measured value block” and further select display group – 098. Check idling switch at idle stop in the display field 3.
  • Page 236 Bridge contacts 3 + 7 of the plug – connection with adapter cables and observe the read-out on the display. Display 0: End the test using the function 06 “End – output”. Replace throttle valve control unit – → Chapter. Display 1: End the test using the function 06 “End –...
  • Page 237 measured value block” and further select display group 098. Check the operating state of the throttle valve control unit in display field 3. Reading measured value block 98 Specified value: 00000000 -> 4.20 V 3.48 V 00000000 Meaning of the digits in the 8-digit numerical block for the operating condition of the throttle valve control unit: xxxx...
  • Page 238 Read off throttle valve angle in display field 3. Specified value: 1.9...5.7 ∠°. Slowly open the throttle valve completely and by doing so – observe the angle indicator in display field 3. The numerical value must increase evenly over the total range. –...
  • Page 239 control unit -2-. Measure resistance of throttle valve – positioner between the contacts 1 + 2: Specified value: 3...200 Ω If the specified value is not reached: Replace throttle valve control unit – → Chapter. If the specified value is reached: Test voltage supply of throttle valve –...

  • Page 240: Adapt The Engine Control Unit To The Throttle Valve Control Unit

    current flow diagram. Contact at 8-pin plug Contact to text box Cable resistance: max. 1.5 Ω – Additionally test wiring to each other for short-circuit. Specified value: ∞ Ω If the cable is not found to be faulty: – Test voltage supply of engine control unit →...
  • Page 241 – Enter function 04 “Initiate basic setting” and further select display group 098. The following appears in the display: After the Q key has been pressed, the throttle valve positioner moves from the min. limit (throttle valve is closed) up to the max. limit (throttle valve is opened).

  • Page 242: Test Intake Manifold Changeover

    See fault table → Chapter, fault code 01087. The reason for an unsuccessful adaptation of the throttle valve control unit can also be detected by selecting the display group 001 (read measured value block, when ignition is switched on) → Chapter.

  • Page 243: Inspect The Vacuum System

    The vacuum box for the intake manifold – switch-over must pull in, the shift linkage must go back again to its initial position -arrow-. If the change-over does not occur, perform the following tests: Check variable intake manifold – changeover valve -N156- (perform final control diagnosis →...

  • Page 244: Test Variable Intake Manifold Changeover Valve -N156

    – If necessary replace vacuum unit. If the vacuum unit does not connect, test valve -N156- for continuity as follows: Connect one contact of the valve°with the – connection line and alligator clip from -V.A.G 1594 A- to the engine mass. Lay a second contact of the valve with remote control - V.A.G 1348/3A-, adapter cable –...
  • Page 245 Specified value: 25 to 35 Ω. If the specified value is not reached, replace the variable intake manifold changeover valve. Test voltage supply and actuation of the variable intake manifold changeover valve -N156- Disconnect plug at variable intake – manifold changeover valve. Connect the voltage tester to contact 1 –...
  • Page 246 -V.A.G 1598/22- to the wiring loom of the engine control unit → Chapter. If the voltage tester lights up continuously, test the wiring of contact 2 – of the plug for variable intake manifold changeover valve to socket 64 of the test box for short circuit to earth.

  • Page 247: Testing Auxiliary Signals

    Testing auxiliary signals Inspecting AC compressor disconnection Note t The engine control unit has the possibility to deactivate the AC compressor. The deactivation of the AC compressor is performed at maximum load (full throttle) in the first gear (on vehicles with manual gearbox). t There is no deactivation of the AC compressor on vehicles with automatic gearbox.
  • Page 248 on). Conduct a test drive in the first gear (press down – the gas pedal promptly at low speed). During the acceleration, the display in the display field 4 must show “0” (during this period the AC compressor is Reading measured value block 19 ->...
  • Page 249 Vehicle system tester -V.A.G 1552 - with cable -V.A.G 1551/3- Measuring tool set -V.A.G 1594 A - Test box -V.A.G 1598/22- Note A positive signal is applied to contact 8 at the engine control unit by switching on the air conditioning system.
  • Page 250 Display field 3 must display “1”. Display field 4 (1st position from right) must display “1” (compressor on). For all vehicles Apart from a momentary engine speed reduction, the idling speed must remain constant. Reading measured value If the speed is not maintained constant, switch off the engine block 19 –...
  • Page 251 – Foot brake activated and engage a driving position. Display field 2 must display “1”. If the readout in the display is not as described, connect the test – box -V.A.G 1598/22- at wiring loom to the engine control unit →...
  • Page 252 Test engine speed signal Note The engine speed signal is shown at contact 6 of the engine control unit. The signal, amongst others, is absolutely necessary for the automatic gearbox control unit for calculating the gear-change points and for the rev counter readout in the dash panel insert. Connect the test box -V.A.G 1598/22 - to the wiring loom of the engine control unit –...
  • Page 253 Test the wiring of contact 7 of the engine control unit connector to the automatic gearbox – control unit for interruption or short-circuit → Current flow diagrams and Fitting locations. For vehicles 08.97 ► Test the wiring of contact 8 of the engine control unit connector to the automatic gearbox –...
  • Page 254 If the voltage tester does not flash, test the wiring of contact 20 – at plug of engine control unit to dash panel insert for open circuit and/or short circuit → Current flow diagrams and Fitting locations. Check signal for gearbox intervention during gearshifts Note By means of this signal from the automatic gearbox control unit, the ignition angle is briefly reduced (torque reduction) depending upon the speed and engine speed during...
  • Page 255 If the automatic gearbox control unit requests an ignition angle relief, the display quickly jumps from “0” to “1”. The wiring to the automatic gearbox control unit is monitored – by the gearbox self-diagnosis (fault code 00545). During gearshifts, if no read-out for the torque reduction is performed in the measured value block or the fault code 00545 (in the automatic gearbox control unit) is shown: For vehicles ►...
  • Page 256 Unplug the 2-pin connector -1- from the – PAS pressure switch -F88--2-. Check wiring between the test box and – the 2-pin plug for interruption according to the current flow diagram, cable resistance: max. 1.5 Ω. Contact at 2-pin plug Contact to test box 1598/22 –...
  • Page 257 Test sequence Connect vehicle system tester -V.A.G 1552- and select address word 01 “Engine – electronics”. Engine idling. Select 08 for the function “read measured value block” and further select display group – 019. Observe display value in the display field 4. (3rd position from right).
  • Page 258 Test data bus Engine control unit – Fitting location: in plenum chamber ABS control unit Fitting location: at the hydraulic unit in – left of engine compartment Gearbox control unit – Fitting location: in plenum chamber Databus driver – Part of control unit Operation The engine control unit -1- communicates with the ABS control unit -2- and the...
  • Page 259 Before starting the test, the fault memories of the control units which are connected to the engine control unit via the data bus must be interrogated (automatic test sequence, address word 00). Self-diagnosis has determined a fault in the data bus. The ABS control unit is coded for the data bus operation.
  • Page 260 Unlock plug connection and remove from – ABS control unit. Check CAN databus cables for short – circuiting with each other: Measure resistance between test box – sockets 29 and 31. Specified value: ∞ Ω. If the specified value is not reached (there is a short-circuit between the cables): Eliminate the fault in the wiring –...
  • Page 261 ABS control unit. Check the cables between the engine – control unit and the ABS control unit for short-circuit to positive and/or to earth. If the lines are not found to be faulty: – Fit again plug onto engine control unit. Connect test box -V.A.G 1598/21 --1- to –...
  • Page 262 Connect and lock the test box – -V.A.G 1598/18 --1- to wiring loom of the gearbox control unit -1--2-. Check CAN databus cables with the – terminating resistance in the engine and ABS control unit: Measure resistance between test box –...
  • Page 263 – Release connector from engine control unit and unplug. – Check databus cables with the terminating resistance in the ABS control unit: – Measure the resistance between bushes 3 + 25 of the test box 1598/18. For vehicles ► 04.99 Specified value: 115...135 Ω.
  • Page 264 Test CAN databus cables Unlock plug connection and remove from – ABS control unit. Release connector from engine control – unit and unplug. Check CAN databus cables for short – circuiting with each other: Measure the resistance between bushes – 3 + 25 of the test box 1598/18.
  • Page 265 If the lines are not found to be faulty: Connect test box -V.A.G 1598/21-1- - to – wiring loom of the ABS control unit -2-. Check CAN databus cables between the – test box bushes 1598/22 and 1598/21 for interruption according to the current flow diagram: resistance: max.

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