Test K

PINPOINT TEST K: THE A/C IS ALWAYS ON

Test K1-K3:

Test K4-K5:

Test K6-K7:

Test K8-k9:

Normal Operation
Under normal operation, the Dual Automatic Temperature Control (DATC) module sends a A/C request signal over the communication bus to the PCM. The thermostatic switch and low charge protection switch receive a ground through circuit 570 (BK/WH). The thermostatic switch receives ignition voltage through circuit 1139 (VT/YE). When the thermostatic switch closes, a signal is sent to the PCM through circuit 347 (BK/YE). When the low charge protection switch closes, ground is provided to the high pressure cutoff switch through circuit 439 (TN/LG). When the high pressure cutoff switch closes, a ground signal is received by the PCM through circuit 441 (RD/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 1139 (VT/YE). Ignition voltage for the A/C clutch relay switch is provided through circuit 1003 (GY/WH). 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 1205 (BK).

Possible Causes
- A short to ground in circuits 331 (PK/YE) or 441 (RD/YE).
- A short to voltage in circuit 347 (BK/YE) or 321 (GY/WH).
- PCM.
- DATC module.
- A/C compressor clutch field coil.
- A/C control relay.