+30 Power Supply Circuit

Fault symptom
The anti-theft alarm does not work.


Important: Failure of the power supply (+30 circuit) for the electronic control module will result in total loss of alarm functions.
Check the +30 power supply circuit by arming and disarming the anti-theft alarm.
For US/CA, start fault diagnosis as described in point 1
For EU, start fault diagnosis as described in point 2






Diagnostic procedure
1 Check fuse 23.
- Check that fuse 23 is intact and live.
- Connect the test lamp to the fuse and a good grounding point.
The test lamp should light up.
Does it light up?
[YES] Continue with point 2.
[NO] Continue fault diagnosis in +30 power supply". Electrical Diagrams

2 Check the power supply (+30 circuit)
- Unplug connector H33-3.
- Connect the test lamp to pin 5 of connector H33-3 and a good grounding point.
The test lamp should light up.
Does the lamp light up?
[YES] Proceed to point 4.
[NO] Continue with point 3.







3 Check the wiring connected to the fuses
- US/CA
Connect the test lamp to fuse 23 and a good grounding point.
The test lamp should light up.
Does it light up?
[YES] Check and repair or replace the wiring between pin 5 of connector H33-3 and fuse 23.
[NO] Continue fault diagnosis as described in Service Manual 3:2 "Electrical system, +30 power supply".

- EU
Connect the test lamp to fuse 1 and a good grounding point.
The test lamp should light up.
Does it light up?
[YES] Check and repair or replace the wiring between pin 5 of connector H33-3 and fuse 1.
[NO] Continue fault diagnosis in +30 power supply". Electrical Diagrams






4 Check the wiring connected to the electronic control module
Check the wiring harness for continuity between pin 5 of connector H33-3 and pin 25 of the electronic control module.
The resistance should be < 1 ohm.
Is the resistance OK?
[YES] Continue with point 5.
[NO] Repair or replace the wiring harness.

5 Final test
Check the operation of the anti-theft alarm to see whether the fault symptom persists.
Does the trouble persist?
[YES] Continue as described in "Before Changing The Electronic Control Module".
[NO] The remedial measures taken were correct or the fault is of intermittent nature.