Porsche 1989 944 S2, Workshop Manual

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24/28
Fuel System - Electronic Control 944 S/944 S2
Fault, Fault Code Possible Causes, Elimination, Remarks
Tank venting valve is not activated permanently.
Test must be performed within 7 minutes after starting an engine having
operating temperature (interrupt tank venting valve activation approx. 75
seconds afterward and then continue).
Start engine and accelerate. This must be displayed in the tester for an engine
at operating temperature:
Signal will be wider as the air flow rate increases!
Check path according to the wiring diagram if there is no signal.
Replace control unit if necessary.
Test Point
17:
Check
Engine
warning
lamp
Fault Code
1_45
(California as
of
1991 models)
A ground signal from control unit plug terminal 22 goes to and switches on the
"Check Engine Lamp", if a component influencing emission control fails.
If the "Check Engine" warning lamp fails, this fault is stored in the fault
memory.
Check by supplying ground to control unit plug terminal 22 and turning on the
ignition.
Always replace a faulty display lamp with a specified lamp.
D 24/28 - 20 DME - Diagnosing/Troubleshooting
Printed In Germany - XXI, 1989