Skoda OCTAVIA MK1 Service Manual 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.
If the speed is not maintained constant, switch off the engine
–
and connect the test box -V.A.G 1598/22 - at wiring loom to the
engine control unit
Test the wiring of contact 8 at the engine control unit to the air
– conditioning system control unit for interruption or short-circuit
according to the current flow diagram
and Fitting locations.
If there is no fault in the wiring, check the function of the air
– conditioning system
→ Rep. Gr.87.
Check selector lever positions of the automatic gearbox
Special tools and workshop equipment required
t Handheld multimeter, e.g. -V.A.G 1526 A -
t Voltage tester, e.°g. - V.A.G 1527-
t Vehicle system tester -V.A.G 1552 - with cable -V.A.G 1551/3-
t Measuring tool set -V.A.G 1594 A -
t Test box -V.A.G 1598/22-
Note
The engine control unit receives the information if a gear is engaged (selector lever in
t 1/2/3/R/D) or not (selector lever in P or N) from the relay for starter interlock switch and
reversing light -J226-.
The relay for starter interlock switch and reversing light -J226- switches in the selector
t
lever position P or N earth to the contact 22 at the engine control unit.
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
–
019.
The following appears in the display:
Display field 2 must display "0" (selector lever in P or N).
→ Chapter.
→ Heating and Air conditioning system
→ Current flow diagrams
250
Reading measured value
block 19
->
850/rpm 0
00000001
Reading measured
value block 19
->
850/rpm 0
1
1