P0484

P0484-COOLING FAN OVER CURRENT

For a complete wiring diagram, consult the Wiring Information.

Theory of Operation

The Powertrain Control Module (PCM) sends a Pulse-Width Modulated (PWM) signal to the Radiator Fan Module to control speed and a ground signal to the Radiator Fan Relay to control on/off operation.

- When Monitored:
Continuously, with ignition on.

- Set Condition:
The PWM signal from the PCM is drawn above the pre-determined (normal) level.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

2. CHECK FOR OTHER ACTIVE DTC'S

Are DTC's P0480, P0481, P0691, P0692, P0693, or P0694 active?

Yes

- Perform Diagnostics and Repairs for those DTC's before diagnosing this DTC.

No

- Go To 3

3. CHECK THE (A957) RADIATOR FAN MODULE FUSED B+ CIRCUIT FOR AN OPEN OR EXCESSIVE RESISTANCE
1. Turn the ignition off.
2. Unplug the Radiator Fan Module connector.
3. Turn the ignition on, engine off.
4. Using a 12-Volt test light connected to battery ground, probe the (A957) Radiator Fan Module Fused B+ circuit at the Fan Module connector.
5. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Go To 4

No

- Repair the open or excessive resistance in the (A957) Radiator Fan Module Fused B+ circuit. Inspect the related fuse and repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

4. CHECK THE (Z903) RADIATOR FAN MODULE GROUND CIRCUIT FOR AN OPEN OR EXCESSIVE RESISTANCE
1. Turn the ignition off.
2. Unplug the Radiator Fan Module connector.
3. Using a 12-Volt test light connected to battery power, probe the (Z903) Radiator Fan Module ground circuit at the Fan Module connector.
4. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

- Go To 5

No

- Repair the open or excessive resistance in the (Z903) Radiator Fan Module ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. RADIATOR FAN MODULE
1. Replace the Radiator Fan Module
2. Turn the ignition on.
3. Erase the DTC.
4. Run the vehicle up to operating temperature until the Radiator Fans have cycled.
5. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 6

No

- Repair is complete.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

6. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the relay and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Verify that there is good pin to terminal contact at the relay and PCM harness connectors.
5. Perform any Technical Service Bulletins (TSBs) that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module (PCM). .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.