P0481

P0481-COOLING FAN 2 CONTROL CIRCUIT





For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

With the ignition on. Battery voltage greater than 10 volts.

- Set Condition:

The PCM receives a CAN Bus message from the FCM indicating an open or shorted circuit on the Radiator Fan High Relay Control circuit.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. RADIATOR FAN HIGH RELAY OPERATION

Turn the ignition on.
With a scan tool, actuate the Radiator Cooling Fan Relay #2 Control State.

Is the Cooling Fan Relay operating?

Yes

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking for an Intermittent DTC
- Perform the PCM Verification Test Ver. 1. PCM Verification Test

No

- Go to 2

2. FUSED B+ CIRCUITS





Turn the ignition off.
Remove the Radiator High Fan Relay.
Using a 12 volt test light connected to ground, probe the Fused B+ circuits in the Relay connection.

Is the test light illuminated and bright?

Yes

- Go to 4

No

- Go to 3
-

3. RADIATOR FAN HI/LO CONTROL RELAY SHORTED INTERNALLY

With the test light still at the Fused B+ circuit (Radiator High Fan Relay), remove the Radiator Fan HI/LO Control Relay.

With the relay removed, is the test light illuminated and bright?

Yes

- Replace the Radiator Fan HI/LO Control Relay.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Repair the open circuit or short to ground in the Fused B+ circuits. Inspect the related fuse and repair as necessary.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

4. RADIATOR FAN HIGH RELAY CONTROL CIRCUIT





Turn the ignition on.
With a scan tool, actuate the Radiator Cooling Fan Relay #2 Control State to toggle.
Using a 12-volt test light connected to 12 volts, check the Radiator Fan High Relay Control circuit in the PDM.

Does the test light toggle appropriately during the actuation?

Yes

- Replace the Radiator Fan High Relay.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go to 5

5. (N112) RADIATOR FAN HIGH RELAY CONTROL CIRCUIT OPEN





Remove the FCM from the PDM.
Measure the resistance of the (N112) Radiator Fan High Relay Control circuit from the Relay connection to the FCM PDM - 49 way connector.

Is the resistance below 5.0 ohms?

Yes

- Go to 6

No

- Replace the PDM.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

6. (N112) RADIATOR FAN HIGH RELAY CONTROL CIRCUIT SHORTED TO GROUND





Measure the resistance between ground and the (N112) Radiator Fan High Control circuit at the Relay connection.

Is the resistance below 100 ohms?

Yes

- Go to 7

No

- Replace the Front Control Module.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

7. RADIATOR FAN HI/LO CONTROL RELAY SHORTED INTERNALLY

With the probe still at the (N112) Radiator Fan High Control circuit, remove the Radiator Fan HI/LO Control Relay.

Is the resistance still below 100 ohms?

Yes

- Repair the short to ground in the (N112) Radiator Fan High Control circuit.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Replace the Radiator Fan HI/LO Control Relay.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test