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
REFRIGERATION SYSTEM NOT PROPERLY CHARGED
HIGH PRESS CUT-OFF SWITCH
LOW PRESSURE SWITCH
POWERTRAIN CONTROL MODULE
A/C CLUTCH COIL
A/C COMPRESSOR CLUTCH GROUND CIRCUIT OPEN
(C3) A/C CLUTCH RELAY OUTPUT CIRCUIT OPEN
A/C REQUEST CIRCUIT OPEN
(A17) FUSED B+ CIRCUIT OPEN
A/C CLUTCH RELAY
A/C - HEATER CONTROL MODULE
BODY CONTROL MODULE
A/C ON/OFF CONTROL CIRCUIT OPEN
A/C ON/OFF CONTROL CIRCUIT OPEN
CHECKING A/C SYSTEM OPERATION WITH NO DTCS
| 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 | Turn the ignition off. Verify that the Refrigerant System is properly charged per Service Procedure. Is the Refrigerant System properly charged? Yes --> Go To 3 No --> Properly charge the Refrigerant System per Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 3 | Verify the High Pressure Cut-Off Switch operation per Service Information. Is the High Pressure Cut-Off Switch OK? Yes --> Go To 4 No --> Replace the High Pressure Cut-Off Switch. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 4 | Verify the Low Pressure Switch operation per Service Information. Is the Low Pressure Switch OK? Yes --> Go To 5 No --> Replace the Low Pressure Switch. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 5 | Ignition on, engine not running. Position the Mode switch on the A/C - Heater Control Module to the Panel position. 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 6 No --> Go To 13 |
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| 6 | Position the Mode switch on the A/C - Heater Control Module to the Panel position. 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 7 No --> Replace and program the Powertrain Control Module per Service Information. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 7 | Connect a test light between the ground circuit and the A/C Clutch Relay Output circuit. With the DRBIII®, actuate the A/C Clutch Relay. Does the test light illuminate brightly on and off with the relay actuation? Yes --> Replace the A/C Clutch Coil. Perform POWERTRAIN VERIFICATION TEST VER - 2 . No --> Go To 8 |
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| 8 | Turn the ignition off. Disconnect the A/C Clutch harness connector.
NOTE:
Check connectors - Clean/repair as necessary. Measure the resistance between ground and the A/C Compressor Clutch ground circuit in the A/C Clutch harness connector. Is the resistance below 5.0 ohms? Yes --> Go To 9 No --> Repair the open in the A/C Compressor Clutch ground circuit. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 9 | Turn the ignition off. Remove the A/C Clutch Relay.
NOTE:
Check connectors - Clean/repair as necessary. Measure the resistance of the (C3) A/C Clutch Relay Output circuit between the Relay and the A/C Clutch Coil. Is the resistance below 5.0 ohms? Yes --> Go To 10 No --> Repair the open in the (C3) A/C Clutch Relay Output circuit. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 10 | Engine Running. Turn the A/C system on and the fan on high. With the DRBIII® in Inputs/Outputs, read the A/C request state. Does the A/C request state change? Yes --> Go To 11 No --> Repair the open in the A/C Request circuit. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 11 | Turn the ignition off. Remove the A/C Clutch Relay.
NOTE:
Check connectors - Clean/repair as necessary. Measure the voltage of the (A17) Fused B+ circuit at the A/C Clutch Relay connector. Is the voltage above 11.0 volts? Yes --> Go To 12 No --> Repair the open in the (A17) Fused B+ circuit. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 12 | If there are no possible causes remaining, view repair. Repair Replace the A/C Clutch Relay. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 13 | Turn the ignition off. Disconnect the A/C - Heater Control C1 harness connector. Ignition on, engine not running. Measure the voltage between the A/C On/Off Control circuit and ground. Is the voltage greater than 11.0 volts? Yes --> Go To 14 No --> Go To 15 |
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| 14 | Turn the ignition off. Disconnect the A/C - Heater Control C1 harness connector. Ignition on, engine not running. 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 per Service Information. Perform BODY VERIFICATION TEST - VER 1 . |
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| 15 | 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 BCM C1 harness connector and the A/C - Heater Control C1 harness connector. Is the resistance below 5.0 ohms? Yes --> Replace and program the Body Control Module per Service Information. Perform BODY VERIFICATION TEST - VER 1 . No --> Repair the A/C On/Off Control Circuit for an open. Perform BODY VERIFICATION TEST - VER 1 . |
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