Possible Causes Elimination Remarks

Test point 2:

Idle speed contact (a) Ground short

Fault code 1 12

Check by means of circuit input test with system tester 9288 or Tester9268

Select test step and operate accelerator pedal. 9288 display: Idle speed contact closed Idle speed contact open. 9268 display: 1332 (idle speed contact closed) 0000 (idle speed contact open).

No display:

Disconnect plug from DME control unit.

Connect ohmmeter between terminal 52 and terminal 24 using test leads.

Bridge Ground to terminal 30


Throttle valve closed <10

Throttle valve opening angle >1° =

If the values of the idle speed contact are not reached in this test, the test should be repeated directly at the throttle valve switch:

Disconnect the plug on the throttle valve switch. Connect an ohmmeter between terminals 1 and 2 of the throttle valve switch using test leads.


Throttle valve closed <10 Q.

Throttle valve opening angle >1° =

Idle speed contact (£2) Test procedure same as for ground short.

Break (Fault will be stored in memory as from '91 models)

Fault code 1_15 Check whether setting is correct and adjust if necessary.

Cause may be incorrectly set throttle valve switch or accelerator cable, for example.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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