Antitheft and Alarm System

Diagnostic Trouble Code B1605
Fault in the electronic control module

Fault symptom
Anti-theft alarm completely unserviceable. Indefinable (different functions may be affected, due to an internal memory and/or programming fault).

Condition
Electronic control module fault (internal) generates diagnostic trouble code.







Diagnostic procedure
1 Check diagnostic trouble code generation
- Clear the diagnostic trouble code.
- Drive the car on test.
- Check whether the diagnostic trouble code is generated afresh.

Is the DTC generated afresh?
[YES] Continue with point 2.
[NO] The fault is intermittent.

2 Check the anti-theft alarm's electronic control module connection
- Remove the electronic control module.
- Inspect the connector for slide-out of the contact sockets.
- Check the electronic control module's ground and power supply connections:
- pin 25 (+30)
- pin 10 (+15)
- pin 13 (GND)

Everything OK?
[YES] Reinstall the electronic control module and continue with point 3.
[NO] Take remedial action.







3 Check diagnostic trouble code generation
- Clear the diagnostic trouble code.
- Arm/disarm the anti-theft alarm 5 times.
- Check whether the diagnostic trouble code is generated afresh.

Is the DTC generated afresh?
[YES] Continue as described in "Before Changing the Electronic Control Module". Before Changing the Electronic Control Module
[NO] The remedial measure taken was correct or the fault is of intermittent nature.