Fault-Tracing Information

Fault-tracing information

Condition




No communication between Volvo Scan Tool (ST) and immobilizer control module generation 3 (immo 3).

Hint: If uncertain which generation of immobilizer is installed in the car, check according to Visual identification Application and ID

Possible source
If the engine starts:
- Open-circuit, short-circuit to ground or short-circuit to supply voltage in cable to data link connector (DLC) terminal 7.
- Open-circuit in data link connector (DLC) power supply, power ground or signal ground.
- Defective Volvo Scan Tool (ST), defective wiring to Volvo Scan Tool (ST) or defective adapter box.

Possible source
If engine will not start:
- Battery voltage too low
- +15-supply to ground between fuse 11C/4 and immobilizer control module.
- Open-circuit in +15-supply.
- +30- supply short-circuit to ground between fuse 11C/8 and immobilizer control module.
- Open-circuit in +30-supply.
- Open-circuit in immobilizer control module ground lead or bad ground terminal.
- Cable between engine control module (ECM) and control module immobilizer #4 is short-circuited to ground or voltage.

Note! If the communication problem only occurs when stationary with ignition on or when starting engine, but not when the engine is running: Connect an battery charger or extra battery.