Pinpoint Test 11: The Air Conditioning (A/C) Is Always On - A/C Mode Always Commanded On

PINPOINT TEST 11: THE AIR CONDITIONING (A/C) IS ALWAYS ON - A/C MODE ALWAYS COMMANDED ON

Normal Operation

Voltage is supplied to the A/C low charge protection switch through circuit (G/BR). When the A/C low charge protection switch is closed (ON), voltage is sent to the dual-function pressure switch through circuit (V). When the dual-function pressure switch is closed (ON), voltage is provided to the PCM. Ignition voltage is provided to the A/C clutch relay switch through circuit (GY/R). When A/C is requested, a message is sent over the bus to the PCM. When the PCM energizes the relay, ignition voltage is supplied to the A/C clutch through circuit (V/W). Ground is supplied for the A/C clutch through circuit (B/G).

Possible Causes
- Wiring, terminals or connectors
- PCM
- EMTC module

Diagnostic Procedure

NOTE:Before carrying out the following test, diagnose any instrument cluster DTCs.
NOTE:When disconnecting and reconnecting the pressure transducer electrical connector, make sure that the connector-locking device is in place and that the locking device and connector are correctly and fully seated.