Diagnostic Test

1) LOW SPEED RADIATOR FAN RELAY OPERATION
NOTE: If the P0480 is setting on a 5.7L engine, refer to P1646-HYDRAULIC COOLING FAN CONTROL CIRCUIT LOW .

Ignition on, engine not running.

With a scan tool, actuate the Low Speed Radiator Fan Relay.

Is the Cooling Fan Relay operating?

Yes
1. Refer to INTERMITTENT CONDITION Diagnostic Procedure.
No
1. Go to 2).
2) FUSED B+ CIRCUITS

Fig 1: Checking Internal Fused B+ Circuits
Courtesy of CHRYSLER LLC

Turn the ignition off.

Remove the Radiator Fan Low Relay.

Using a 12-volt test light connected to ground, probe the Fused B+ circuits.

Does the test light illuminate brightly?

Yes
1. Go to 3).
No
1. Repair the open or short to ground in the Fused B+ circuits. Inspect the related fuse and repair as necessary.
2. Perform POWERTRAIN VERIFICATION TEST .
3) RADIATOR FAN LOW RELAY RESISTANCE
Measure the resistance of the Radiator Fan Low Relay Coil.

Is the resistance between 60 to 80 ohms?

Yes
1. Go to 4).
No
1. Replace the Radiator Fan Low Relay.
2. Perform POWERTRAIN VERIFICATION TEST .
4) RADIATOR FAN LOW RELAY CONTROL CIRCUIT OPEN

Fig 2: Checking Cooling Fan No. 1 Control Circuit For Open
Courtesy of CHRYSLER LLC

Disconnect the C3 FCM harness connector.

Measure the resistance of the Radiator Fan Low Relay Control circuit from the Relay to the C3 FCM harness connector.

Is the resistance below 5.0 ohms?

Yes
1. Go to 5).
No
1. Repair the open in the Radiator Fan Low Relay Control circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
5) RADIATOR FAN LOW RELAY CONTROL CIRCUIT SHORTED TO GROUND

Fig 3: Checking Cooling Fan No. 1 Control Circuit For Short To Ground
Courtesy of CHRYSLER LLC

Measure the resistance between ground and the Radiator Fan Low Relay Control circuit at the Relay connection.

Is the resistance below 100 ohms?

Yes
1. Repair the short to ground in the Radiator Fan Low Relay Control circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 6).
6) FRONT CONTROL MODULE (FCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Radiator Fan and the Front Control Module (FCM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Radiator Fan High Relay and Front Control Module connectors.

Refer to any Technical Service Bulletins that may apply.

Were there any problems found?

Yes
1. Repair as necessary.
2. Perform BODY VERIFICATION TEST .
No
1. Replace Front Control Module per Service Information.
2. Perform BODY VERIFICATION TEST .