Possible Causes
WARNING: This page is about a different car, the 2005 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.
CHECK FOR PCM DTCS
POWERTRAIN CONTROL MODULE
A/C CLUTCH
A/C CLUTCH RELAY OUTPUT CIRCUIT SHORTED TO VOLTAGE
A/C CLUTCH RELAY
CHECK A/C ON/OFF CONTROL CIRCUIT FOR A SHORT TO GROUND
A/C - HEATER CONTROL MODULE
BODY CONTROL MODULE
A/C OPERATES IN ALL MODE SWITCH POSITIONS
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 | With the DRBIII®, check for PCM DTCs. Are any DTCs present? Yes --> Return to the symptom list and choose the symptom(s). Perform POWERTRAIN VERIFICATION TEST VER - 2 . No --> Go To 2 |
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| 2 | Position the Mode switch on the A/C - Heater Control Module to the Panel position. Turn the ignition on. With the DRBIII® in BCM, select Inputs/Outputs. Monitor the A/C Select Switch state while pressing the A/C mode switch on and off. Does the A/C Select Switch state change accordingly. Yes --> Go To 3 No --> Go To 6 |
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| 3 | Position the Mode switch on the A/C - Heater Control Module to the Panel position. Turn the ignition on. With the DRBIII® in Powertrain, select Engine and select Inputs/Outputs. Monitor the A/C Select Switch state while pressing the A/C mode switch on and off. Does the A/C Select Switch state change accordingly. Yes --> Go To 4 No --> Replace and program the Powertrain Control Module per Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 4 | Turn the ignition off. Disconnect the A/C Clutch harness connector. Start the engine and observe the A/C Clutch and Compressor. Does the A/C Compressor run with the harness connector disconnected? Yes --> Replace the A/C Clutch per Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 2 . No --> Go To 5 |
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| 5 | Turn the ignition off. Remove the A/C Clutch Relay from the PDC. Disconnect the A/C Clutch harness connector. Measure the voltage of the A/C Clutch Relay Output circuit. Is the voltage above 1.0 volt? Yes --> Repair the A/C Clutch Relay Output circuit for a short to voltage. Perform POWERTRAIN VERIFICATION TEST VER - 2 . No --> Replace the A/C Clutch Relay. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 6 | Turn the ignition off. Disconnect the BCM C1 harness connector. Disconnect the A/C - Heater Control C1 harness connector. Measure the resistance of the A/C On/Off Control circuit between the A/C - Heater Control C1 harness connector and ground. Is the resistance below 10K ohms? Yes --> Repair the A/C On/Off Control Circuit for a short to ground. Perform BODY VERIFICATION TEST - VER 1 . No --> Go To 7 |
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| 7 | Turn the ignition off. Make sure that the BCM C1 harness connector is connected to the BCM. Disconnect the A/C - Heater Control C1 harness connector. Turn the ignition on. With the DRBIII® in BCM, select Inputs/Outputs. Monitor the A/C Select Switch state while connecting a jumper wire between ground and the A/C On/Off Control circuit in the A/C - Heater Control C1 harness connector. Does the A/C Select Switch state change from "Off" to "On" when the jumper wire is connected. Yes --> Replace the A/C - Heater Control Module in accordance with the Service Information. Perform BODY VERIFICATION TEST - VER 1 . No --> Replace and program the Body Control Module in accordance with the Service Information. Perform BODY VERIFICATION TEST - VER 1 . |
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