Diagnostic Procedure
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.
P0645-A/C CLUTCH RELAY CIRCUIT DIAGNOSTIC TEST REFERENCE
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 | Ignition on, engine not running. With the DRBIII®, actuate the A/C Clutch Relay. Is the A/C Clutch Relay operating? Yes --> Refer to the INTERMITTENT CONDITION SYMPTOM . Perform POWERTRAIN VERIFICATION TEST VER - 2 . No --> Go To 2 |
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| 2 | Turn the ignition off. Remove the A/C Clutch Relay from the PDC. Ignition on, engine not running. Using a 12-volt test light connected to ground, probe the (F1) Fused Ignition Switch Output circuit. Does the test light illuminate brightly? Yes --> Go To 3 No --> Repair the open or short to ground in the (F1) Fused Ignition Switch Output circuit. Inspect and replace any open fuses. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 3 | Turn the ignition off. Using a 12-volt test light connected to ground, probe the (A112) Fused B+ circuit of the fuel pump relay in the PDC. Does the test light illuminate brightly? Yes --> Go To 4 No --> Repair the open or short to ground in the (A112) Fused B+ circuit. Inspect and replace any open fuses. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 4 | Turn the ignition off. Measure the resistance of the A/C Clutch Relay Coil. Is the resistance between 60 to 80 ohms? Yes --> Go To 5 No --> Replace the A/C Clutch Relay. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 5 | Disconnect the C3 PCM harness connector.
CAUTION:
DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS. Measure the resistance of the (C13) A/C Clutch Relay Control circuit from the PDC to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms? Yes --> Go To 6 No --> Repair the open in the (C13) A/C Clutch Relay Control circuit. Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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| 6 | Measure the resistance between ground and the (C13) A/C Clutch Relay Control circuit in the PDC. Is the resistance below 5.0 ohms? Yes --> Repair the short to ground in the (C13) A/C Clutch Relay Control circuit. Perform POWERTRAIN VERIFICATION TEST VER - 2 . No --> Go To 7 |
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| 7 |
NOTE:
Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.If there are no possible causes remaining, view repair.RepairReplace and program the Powertrain Control Module per Service Information.Perform POWERTRAIN VERIFICATION TEST VER - 2 . |
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