Fault Conditions

P0502
Vehicle Speed. No input signal.

Fault symptoms
- CHECK ENGINE.
- Cruise control not working.
- Low engine torque on cars with manual gearbox.

On-Board Diagnostics
Type of diagnosis:
- Continuous. But interrupted when fault criteria fulfilled and does not restart until next driving cycle.

Enable conditions:
- Engine running. Engine coolant temperature above 60°C. Engine speed above 2000 rpm. Load over 335 mg/c. Brake pedal not depressed.

Fault criteria:
- No vehicle speed for more than 5 S.

Then, 17 minutes without the vehicle speed leaving 0. On automatic cars, the selector lever must also have another value than P or N. Enable criteria for these two fault criteria need not be fulfilled.

Dependents:
- P1576 and P1577.

System reaction to a fault:
- Cruise control blocked. Vehicle speed (Bus from MIU) used as substitute value.

OK report:
- 60 S has expired since start. Vehicle speed has exceeded 0 on some occasion.

Fault handling: See "Fault diagnosis, general" for more information.
- Type III.

Diagnostic help
Fault diagnosis concerns an electrical fault in connecting leads. (Check if fault is in ABS first.)
Functions in the diagnostic tool related to the fault:
- Diagnostic status for the diagnosis.
- Vehicle Speed (Wire from ABS), unit km/h.

See also the description of readings in "Fault diagnosis, general" for more information.

Checking the wiring
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Observe the multimeter, diagnostic tool or test lamp during the check.

Proceed to Diagnostic Procedures Checking Diagnostic Trouble Codes In the ABS