Step M8

Checking the lead to the alarm control module




- Ignition off.

With an ohmmeter:
Check if there is a break in the signal lead:
- Connect an ohmmeter between the alarm relay base item AL and the central locking relay base item AL2. The ohmmeter should show approx. 0 ohm.




With an ohmmeter:
Check if the signal lead is shorted to ground:
- Connect an ohmmeter between the alarm relay base item AL and the central locking relay base item 31. The ohmmeter should show infinity.

With a voltmeter:
Check if the signal lead is shorted to 12 V:
- Connect a voltmeter between the alarm relay base item AL and the central locking relay base item 31. The voltmeter should show 0 V.

If all readings are correct:
- Continue with step M9. Step M9

If there is a deviation:
There is a break or short in the signal lead between the alarm relay base item AL and the central locking relay base item AL2.
- Check connections. Refer to Fault Alarm Wiring. Checking Leads and Connection

Rectify the fault or renew the lead.
Replace the alarm control module.
Replace the central locking relay.