P1251

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE. Idling speed incorrect Cruise control not working. Starting problems, especially when engine is cold

P1251

Note

The system cannot close the throttle disc

Fault symptoms

•	CHECK ENGINE.

•	Idling speed incorrect

•	Cruise control not working.

•	Starting problems, especially when engine is cold

On-Board Diagnostics

Type of diagnosis:

-	Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.

Enable criteria:

-	Test 1: Engine running. Car in motion.

-	Test 2: Engine running for less than 5 s.

Fault criteria:

-	Test 1 and Test 2: Throttle motor receiving 100% PWM in closing direction.

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

A mechanical fault is preventing the throttle from closing.

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.