Testing The Intake System For Tightness (Unmetered Air); Test Voltage Supply Of Engine Control Unit - Skoda OCTAVIA MK1 Service Manual

If the lines are not found to be faulty:
– Replace air mass meter -G70- with intake air temperature sender -G42-

Testing the intake system for tightness (unmetered air)

Special tools and workshop equipment required
t 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.
t The leak search spray reduces the ignition performance of the mixture. This results in a drop in engine
speed and a considerable increase of the CO content.
t You must comply with the safety instructions on the box.
– Select 08 for the function "read measured value block" and further select display group 001.
The following appears in the display:
– Note engine speed in display field 1.
Note lambda probe voltage in display field 3 and the range
–
in which it fluctuates.
Systematically spray parts of the intake system with engine
–
leak search spray.
If the engine speed or lambda probe voltage does not change:
– Press → key.
Enter 06 for the function "End output" and confirm with key
–
Q.
If the engine speed drops or if the lambda probe voltage
changes:
– Press → key.
Enter 06 for the function "End output" and confirm with key
–
Q.
Check the sprayed location of the intake system for leaks
–
and if necessary eliminate the fault.

Test voltage supply of engine control unit

Special tools and workshop equipment required
t Handheld multimeter, e.g. -V.A.G 1526 A -
t Test box -V.A.G 1598/22-
Note
For checking the voltage supply of the engine control unit see also
005, display field 2.
Test conditions:
l Fuse for engine control unit O.K
Reading measured value block 1
->
850/rpm
0000010
211
→ Chapter.
90°C 0.05V
→ Chapter, display group