P0502

DTC's P0500, P0501, P0502:

DIAGNOSTIC TROUBLE CODES PO5OO, PO5O1, PO5O2
VEHICLE SPEED SIGNAL MALFUNCTIONING OR NOT WORKING AT ALL

Fault symptoms
The SHIFT UP lamp fails to work (certain markets)
Fuel shut-off in all gears
Low boost pressure in 3rd, 4th and 5th gears, manual transmission
Possibly ABS warning lamp on

Conditions.
Brake pedal not operated
Engine speed >2000 rpm
Boost pressure >0.3 bar
No speed signal during the course of 4 seconds

Diagnostic procedure
1. Connect an ISAT scan tool.

- Ignition switched ON.
- Connect the ISAT scan tool to the ABS system and read out diagnostic trouble codes.
- If diagnostic trouble codes B1376, B1377 are displayed, remedy these faults first as necessary.

Diagnostic trouble codes in Trionic may be secondary faults.

2. Raise the front assembly of the car with a jack.
- Ignition switched ON.
- Select "WHEEL SPEED FR" on the ISAT scan tool menu "READ FUNCTIONS".
- Rotate the front right wheel at approx. 1/2 revolution per second.

The ISAT scan tool must show 3-5 km/h.

- If the measured value is correct, continue with step 5.
- If the measured value is incorrect, continue with step 3.

NOTES:
^ If the ECM for the Saab 9000 has been fitted, a diagnostic trouble code for vehicle speed signal will be generated.

^ On cars with automatic transmission the diagnostic trouble code may be generated if there is no input from the brake light switch.

DTC's P0500, P0501, P0502:

3. With the ignition switched OFF, connect a BOB.

- Ignition switched ON.
- Connect the measuring leads to the ISAT scan tool between pins 39 and 67 and select the ISAT menu "MEASURING" and the submenu "PULSE".
- Rotate the front right wheel manually at approx. 1/2 revolution per second and check that pulses are present.

The ISAT scan tool should show approx. 15 Hz.

- If the measured value is correct, continue with step 5.
- If the measured value is incorrect, continue with step 4.

DTC's P0500, P0501, P0502:

4. Check the lead between pin 7 of the ABS ECM and pin 39 of the Trionic ECM for discontinuity/shorting.

- If the lead is OK, continue fault diagnosis in the ABS system.

5. Erase the diagnostic trouble code and drive the car to see whether the DTC is generated again.

- If the diagnostic trouble code is registered, continue at "Procedure before replacing ECM".
- If the diagnostic trouble code is not registered, the action taken is correct. Otherwise the fault is intermittent in nature.