Test K: The Air Conditioning (A/C) Is Always On

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

Normal Operation
Under normal operation, when A/C is requested, in the dual automatic temperature control (DATC) system, a message is sent over the medium-speed controller area network (MS-CAN) bus to the instrument cluster, then from the instrument cluster through the high-speed controller area network (HS-CAN) bus to the PCM; or in electronic manual temperature control (EMTC) systems, voltage is sent to the instrument cluster through circuit CH434 (GY/YE), then a message is sent from the instrument cluster through the HS-CAN bus to the PCM.

Ignition voltage is provided to the A/C clutch relay switch. When the PCM energizes the relay, ignition voltage is supplied to the A/C clutch through circuit CH401 (VT/WH). Ground is supplied for the A/C clutch through circuit GD120 (BK/GN).

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- PCM
- HVAC module - DATC
- HVAC module - EMTC
- A/C evaporator discharge temperature sensor
- A/C pressure transducer
- A/C control relay
- A/C compressor

K1-K3:

K4-K8:

K8-K11:

K11 Continued: