Pinpoint Test J: The Air Conditioning (A/C) is Always On - A/C Mode Always Commanded ON
Climate Control System
Pinpoint Tests
Pinpoint Test J: The Air Conditioning (A/C) is Always On - A/C Mode Always Commanded ON
Refer to Wiring Diagram Set 54, Manual Climate Control System for schematic and connector information. Diagrams By Number
Normal Operation
Under normal operation, when A/C is requested the HVAC module then sends an A/C request message over the Medium Speed Controller Area Network (MS-CAN) bus to the Instrument Cluster (IC), then from the IC through the High Speed Controller Area Network (HS-CAN) bus to the PCM.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- PCM
- HVAC module
PINPOINT TEST J: THE AIR CONDITIONING (A/C) IS ALWAYS ON - A/C MODE ALWAYS COMMANDED ON
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.
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J1 CHECK THE AIR CONDITIONING SWITCH STATUS (CC_AC) HVAC PID WITH THE A/C OFF
- Enter the following diagnostic mode on the scan tool: CC_AC HVAC PID.
- Does the CC_AC HVAC PID read DEPRESSED?
Yes
GO to J4.
No
GO to J2.
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J2 CHECK THE AIR CONDITIONING REQUEST SIGNAL (AC_REQ) PCM PID WITH THE A/C OFF
- Enter the following diagnostic mode on the scan tool: AC_REQ PCM PID.
- Select OFF on the HVAC module.
- Does the AC_REQ PCM PID read YES?
Yes
GO to J5.
No
GO to J3.
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J3 CHECK AIR CONDITIONING COMPRESSOR COMMANDED STATE (ACC_CMD) PCM PID WITH THE A/C OFF
- Enter the following diagnostic mode on the scan tool: ACC_CMD PCM PID.
- Does the ACC_CMD PCM PID read ON?
Yes
GO to J5.
No
GO to J4.
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J4 CHECK THE HVAC MODULE CONNECTION
- Inspect the module connectors for:
- corrosion.
- pushed-out terminals.
- damaged terminals.
- Connect and correctly seat all the HVAC module connectors.
- Clear the DTCs.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new HVAC module. REFER to Climate Control Heating Ventilation Air Conditioning (HVAC) Module. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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J5 CHECK THE PCM CONNECTION
- Clear the DTCs.
- Disconnect all of the PCM connectors.
- Check for:
- corrosion.
- pushed-out connectors.
- incorrectly seated connector.
- Connect and correctly seat all of the PCM connectors.
- Operate the system.
- Does the concern return?
Yes
INSTALL a new PCM. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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