P0502

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE. Cruise control inoperative.

P0502

Fault symptoms

•	CHECK ENGINE.

•	Cruise control inoperative.

On-Board Diagnostics

Type of diagnosis:

-	Continuous.

Enable criteria:

One of the following conditions must be met:

-	Engine speed should be over 2000 rpm.

-	Injection quantity should be 20 mm 3 /combustion.

-	Coolant temperature over 50 °C and no DTCs stored for coolant temperature sensor.

Fault criteria:

-	The vehicle speed signal from ESP is 0 km/h.

Dependents:

-

None.

System reaction to a fault:

-	The following limitations apply: ECM will continue to use a substitute value of 0 km/h and cruise control is switched off.

OK report:

-	The vehicle speed signal from ESP is greater than 0 km/h.

Fault handling: (See section Fault handling III, other emissions-related components and functions for more information)

-

Type III.

Diagnostic help

Fault diagnosis concerns an electrical fault in connecting leads or in the sensor.

Functions in the diagnostic tool related to the fault:

-	Read value: Vehicle Speed

The vehicle speed signal goes via BUS on cars equipped with ESP.

See also description of read value under "Read Values" menu 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.