Test I

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

Test I1:

Test I2-I6:

Test I6-I8:

Test I8 Continued:

Normal Operation
Under normal operation, when A/C is requested a signal is sent from the control module to the Smart Junction Box (SJB) through circuit 1397 (GY/WH) (Single-zone EMTC only) or over the SCP BUS (Dual-zone EATC and EMTC only). The SJB sends a message over the SCP bus to the PCM. Voltage is supplied to the A/C cycling switch by circuit 298 (VT/OG) and to the PCM through circuit 347 (BK/YE).

The PCM provides a ground for the A/C clutch relay coil through circuit 331 (PK/YE). 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 931 (OG). 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
- An open in circuit or 331 (PK/YE).
- A short to voltage in circuit 883 (PK/LB), 1397 (GY/WH) or 331 (PK/YE).
- A short to ground in circuit 331 (PK/YE).
- PCM.
- EATC module.
- EMTC module.
- A/C control relay.
- A/C clutch air gap.