Test E: The Air Conditioning (A/C) Is Always On
PINPOINT TEST E: THE AIR CONDITIONING (A/C) IS ALWAYS ONE1-E2:
E2-E6:
E6-E9:
E9-E12:
E13:
Normal Operation
Under normal operation, when A/C is requested, a ground signal is sent to the smart junction box (SJB) through circuit 1397 (GY/RD) then a message is sent from the SJB through the CAN bus to the PCM. Voltage is provided to the A/C cycling switch through circuit 391 (RD/YE). The PCM receives input from the A/C cycling switch through circuit 420 (DB/YE) and (4.6L only) through the dual function pressure switch to circuit 198 (DG/OG).
The PCM provides a ground for the A/C clutch relay coil through circuit 321 (GY/WH). When the relay is activated, ignition voltage is supplied to the A/C clutch solenoid through circuit 883 (PK/LB). Ground is supplied for the A/C clutch through circuit 1205 (BK).
Possible Causes
- A short to voltage in circuit 883 (PK/LB), 198 (DG/OG) or 420 (DB/YE)
- A short to ground in circuit 1397 (GY/RD)
- PCM
- Smart junction box (SJB)
- EMTC module
- A/C cycling switch
- A/C control relay
- A/C clutch air gap