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

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

Normal Operation
Under normal electronic automatic temperature control (EATC) operation, when A/C is requested, a message is sent over the bus from the EATC module to the PCM. The PCM receives input from the A/C cycling switch through circuit 883 (PK/LB). Voltage is provided to the A/C cycling switch through circuit 348 (RD/VT).

Under normal manual climate control operation, when A/C is requested the function selector switch sends voltage to the A/C cycling switch through circuit 348 (RD/VT). The PCM receives input from the A/C cycling switch through circuit 883 (PK/LB). Voltage is supplied to the function selector switch through circuit 1040 (RD/BK).

The PCM provides a ground for the A/C clutch relay coil through circuit 73 (OG/LB). The A/C clutch relay coil receives ignition voltage through circuit 391 (RD/YE). Ignition voltage for the A/C clutch relay switch is provided through circuit 1810 (LG/OG). When the relay is activated, ignition voltage is supplied to the A/C clutch solenoid through circuit 321 (GY/WH). Ground is supplied for the A/C clutch through circuit 57 (BK).

This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- A/C pressure transducer
- PCM
- A/C control relay
- Function selector switch
- Electronic automatic temperature control (EATC) module
- A/C cycling switch
- A/C compressor clutch field coil
- A/C clutch air gap

I1-I4:

I5-I8:

I8-I10:

I10-I12:

I12-I14:

I14-I15:

I16-I18:

I18-I19:

I20-I21: