Checking the Motronic Control Module Power Supply

Checking the Motronic Control Module Power Supply







Unplug the connector:
- Control module, Motronic 2.10.3 (505)







- Turn the ignition switch to the ON position.












- Connect test lamp 86 11 857 between pin 18 on the control module female connector and a good grounding point.







- The test lamp should light.

Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

Is the function correct?

NO - Rectifying the Lead - II

YES - Continue with Checking the Motronic Control Module Power Supply







- Connect test lamp 86 11 857 between pin 18 on the control module female connector and pin 2.







- The test lamp should light.

Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

Is the function correct?

NO - Rectifying the Lead - II

YES - Continue with Checking the Motronic Control Module Power Supply












- Connect test lamp 86 11 857 between pin 27 on the control module female connector and a good grounding point.







- The test lamp should light.

Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

Is the function correct?

NO - Rectifying the Lead - II

YES - Continue with Checking the Motronic Control Module Power Supply







- Connect test lamp 86 11 857 between pin 27 on the control module female connector and a pin 2.







- The test lamp should light.

Checking the wiring harness.
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

Is the function correct?

NO - Rectifying the Lead - II

YES - Final Check