Test J: The Air Conditioning (A/C) Is Always On

PINPOINT TEST J: THE AIR CONDITIONING (A/C) IS ALWAYS ON

Normal Operation
Under normal operation, when A/C is requested, a message is sent from the electronic manual temperature control (EMTC) or electronic automatic temperature control (EATC) over the medium speed controller area network (MS-CAN) bus to the PCM. Ignition voltage is provided to the A/C clutch relay switch through circuit SBB24 (VT/RD). When the PCM energizes the relay, ignition voltage is supplied to the A/C clutch through circuit CH421 (GY). Ground is supplied for the A/C clutch through circuit GD120 (BK/GN).

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- PCM
- EATC module
- EMTC module
- A/C evaporator discharge temperature sensor
- A/C pressure transducer
- A/C control relay
- A/C clutch air gap

J1-J6:

J6-J9: