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.
P0480-COOLING FAN NO. 1 CONTROL CIRCUIT DIAGNOSTIC TEST REFERENCE
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 | Ignition on, engine not running. With the DRBIII®, actuate the Low Speed Radiator Fan Relay. Is the Radiator Fan Relay cycling on and off? Yes --> Refer to the INTERMITTENT CONDITION SYMPTOM . Perform POWERTRAIN VERIFICATION TEST VER - 5 . No --> Go To 2 |
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| 2 | Turn the ignition off. Remove the Low Speed Radiator Fan Relay from the PDC. Measure the resistance of the Low Speed Radiator Fan Relay Coil by measuring between the (F1) Fused Ignition Switch terminal and the (N201) Control circuit terminal at the Relay. Is the resistance between 60 and 80 ohms? Yes --> Go To 3 No --> Replace the Low Speed Radiator Fan Relay. Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
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| 3 | Ignition on, engine not running. Using a 12-volt test light connected to ground, probe the (F1) Fused Ignition Switch Output circuit at the Relay connector in the PDC. Does the test light illuminate brightly? Yes --> Go To 4 No --> Repair the open or short to ground in the (F1) Fused Ignition Output. Inspect the related fuse and repair as necessary. Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
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| 4 | Turn the ignition off. Remove the Low Speed Radiator Fan Relay from the PDC. Ignition on, engine not running. Measure the voltage on the (A16) Fused B+ circuits in the PDC. Is the voltage above 11.0 volts? Yes --> Go To 5 No --> Repair the open or short to ground in the (A16) Fused B+ circuits. Inspect the related fuse and repair as necessary. Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
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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 (N201) Low Speed Rad Fan 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 (N201) Low Speed Rad Fan Relay Control circuit. Perform POWERTRAIN VERIFICATION TEST VER - 5 . |
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| 6 | Measure the resistance between ground and the (N201) Low Speed Rad Fan Relay Control circuit at the PDC. Is the resistance below 100 ohms? Yes --> Repair the short to ground in the (N201) Low Speed Rad Fan Relay Control circuit. Perform POWERTRAIN VERIFICATION TEST VER - 5 . 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 - 5 . |
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