Test D: The Air Conditioning (A/C) Is Inoperative/Does Not Operate Correctly

PINPOINT TEST D: THE AIR CONDITIONING (A/C) IS INOPERATIVE/DOES NOT OPERATE CORRECTLY

D1-D2:

D2-D4:

D4-D8:

D8-D9:

D9-D11:

D11-D13:

D13-D15:

D15 Continued:

D16-D19:

D19 Continued:

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
- Fuse
- An open in circuit 420 (DB/YE), 1397 (GY/RD), 883 (PK/LB), 198 (DG/OG), 1205 (BK), 391 (RD/YE) or 321 (GY/WH)
- A short to voltage in circuit 1397 (GY/RD)
- PCM
- EMTC module
- A/C cycling switch
- Dual function pressure switch
- A/C compressor clutch field coil
- A/C control relay
- A/C clutch air gap