Test K: The A/C Does Not Operate/Does Not Operate Correctly

PINPOINT TEST K: THE A/C DOES NOT OPERATE/DOES NOT OPERATE CORRECTLY

K1-K3:

K3-K7:

K7-K10:

K10-K12:

K13-K15:

K16-K18:

K18-K20:

Normal operation
Under normal operation, when A/C is requested, a message is sent over the bus to the PCM (EATC systems) or sends voltage to the PCM through circuit CH443 (GN/OG) (manual climate control systems). The PCM receives input from the A/C cycling switch through circuit CH423 (YE). Ground is provided to the A/C cycling switch through circuit GD113 (BK/YE).

The PCM provides a ground for the A/C clutch relay coil through circuit CH302 (WH/BN). The A/C clutch relay coil receives ignition voltage through circuit CBB40 (YE/GN). Ignition voltage for the A/C clutch relay switch is provided through circuit SBB35 (BU/RD). When the relay is activated, ignition voltage is supplied to the A/C clutch solenoid through circuit CH401 (VT/WH). Ground is supplied for the A/C clutch through circuit GD120 (BK).

Possible Causes
- Fuse(s)
- An open in circuits CH423 (YE), CH443 (GN/OG), CBB40 (YE/GN), GD113 (BK/YE), CH423 (YE), GD120 (BK), SBB35 (BU/RD), CH401 (VT/WH) or CH302 (WH/BN)
- A short to voltage in circuit CH443 (GN/OG) or CH302 (WH/BN)
- A short to ground in circuit CH423 (YE)
- PCM
- (EATC systems) EATC module
- (Manual climate control systems) Function selector switch
- A/C cycling switch
- A/C compressor clutch field coil
- A/C control relay
- A/C clutch air gap