Porsche 944 - Manual (Page 151)

944 S/944 S2 Fuel System - Electronic Control
24/28
Fault, Fault Code Possible Causes, Elimination, Remarks
If no display: Disconnect plug on air flow sensor. Connect an ohmmeter on air
flow sensor terminals 1 and 4 with help of test leads. Display: same as above.
Note: In case of a break, there will be a replacement value equal to an intake
air temperature of 20° C (emergency running program).
Test Point 10
Knock sensor
I
Fault Code
1_31
Knock sensor I: Knock signal not plausible. Check:
-
-
-
-
Installation of knock sensor (check tightening torque and type of screw).
Wire harness and plug connections according to wiring diagram.
Reconnecting sensors eliminates contact resistance.
Whether coolant or other liquids are in area of the knock sensor.
Replace knock sensor.
Ignition timing retarded by 6° on crankshaft in case of a faulty knock sensor.
Test Point 11
Knock sensor
II
Fault Code
1_32
Knock sensor II: Knock signal not plausible. Check:
-
-
-
-
Installation of knock sensor (check tightening torque and type of screw).
Wire harness and plug connections according to wiring diagram.
Reconnecting sensors eliminates contact resistance.
Whether coolant or other liquids are in area of the knock sensor.
Replace knock sensor.
Ignition timing retarded by 6" on crankshaft in case of a faulty knock sensor.
DME - Diagnosing/Troubleshooting
Printed In Germany - XXI, 1989
D 24/28 - 17