Fault Conditions

P1605
Internal Control Module. Malfunction.

Fault symptoms
- CHECK ENGINE.
- Incorrect idle speed.
- Cruise control inoperative.

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

Enable criteria:
- Ignition in ON position.

Fault criteria:
- Serial communication fault between processors 339 and 592.

Dependents:
- None.

System reaction to a fault:
- Throttle control goes into limp-home mode. The limp-home solenoid will be activated 5 times in succession each time the ignition is turned on until the fault has been rectified and the trouble codes cleared.

OK report:
- Accelerator pedal has been depressed at some time and then fully released. 120 S has expired since then without fault criteria being fulfilled.

Fault handling: See "Fault diagnosis, general" for more information.
- CHECK ENGINE goes on immediately and can be turned off only by clearing the trouble codes.

Diagnostic help
Fault diagnosis concerns an internal fault in the control module.

Proceed to Diagnostic Procedures Changing Components