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Test Point 2 - Idle Speed Contact

TEST POINT 2 - Idle speed contact - Short to ground - Fault code 1_12

Possible Causes, Elimination, Remarks
Check by means of circuit input test with 9288 system tester, or 9268 tester

- Select the test step and depress the 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 plugs from EZK and LH control unit.




- Connect ohmmeter between terminals 2 and 5, using test leads.

Display:
Throttle valve closed < 10 Ohms
Throttle valve opening angle > 1° = infinite resistance

The idle speed contact must open immediately.

Open circuit: Ignition timing at idle speed approx. 20° CS (crankshaft rotation).
No fuel cutoff when coasting, higher idle speed.

Short circuit: Fuel cutoff as engine runs up, once after every engine start. Ignition timing approx. 10° retarded.

- If the idle speed contact values are not obtained in this test, repeat it directly at the throttle valve switch.




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

Display:
Throttle valve closed < 10 Ohms
Throttle valve opening angle > 1° = infinite resistance

IDLE SPEED CONTACT - Open circuit - Fault code 1_15

Possible Causes, Elimination, Remarks
Test procedure same as for short to ground.
Check that setting is correct and adjust if necessary.
Cause may be incorrectly set throttle valve switch or accelerator cable, for example.