Fault Diagnosis, AC

FAULT DIAGNOSIS, AC

Symptom of fault
The AC compressor does not work.

Conditions.
For the Trionic system to activate the AC compressor, the engine must have been started and the pressure sensor and throttle position sensor must be OK.

Diagnostic procedure
1. Start the engine.

- Connect an ISAT scan tool.
- Contact the Trionic system. Select "READ ON/OFF" and the command "AC IN" in the ISAT.
- Activate the compressor from the facia:
^ Manual AC: fan ON and AC button depressed.
^ ACC: select AUTO position.

NOTE: The anti-freeze thermostat periodically breaks the signal between Integrated Central Electronics (ICE) and Trionic.

The ISAT must show ON and the engine speed must rise.
If this does not happen, the fault is before Trionic.

- Continue fault diagnosis in the air-conditioning system, ACC.
- Stop the engine, then switch the ignition ON again.

2. Select "ACTIVATE" and the "AC OUT" command in the ISAT.
Both the AC relay and the compressor coupling must now be audible.

- If not, the fault is after Trionic.
- Continue fault diagnosis in the air conditioning system, ACC.