P0481-COOLING FAN 2 CONTROL CIRCUIT

For a complete wiring diagram Refer to Section 8W.

When Monitored:
With the ignition on. Battery voltage greater than 10 volts.
Set Condition:
An open or shorted circuit is detected in the High Speed Rad Fan Control circuit. One Trip Fault. Three good trips to turn off the MIL.

Possible Causes

(A16) FUSED (B+) CIRCUITS

(N112) RAD FAN RELAY CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE

(N112) RAD FAN RELAY CONTROL CIRCUIT OPEN

(N112) RAD FAN RELAY CONTROL CIRCUIT SHORTED TO GROUND

MED/HIGH RAD FAN RELAY

SERIES/PARALLEL RAD FAN RELAY

TOTALLY INTEGRATED POWER MODULE

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

1.RADIATOR COOLING FAN MODULE OPERATION

Are both cooling fan operating at medium speed?

Yes

Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2.(A16) FUSED B+ CIRCUIT

Does the test light illuminate brightly at each terminal?

Yes

Repair the (A16) Fused B+ circuit. Inspect the related fuse and repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

3.MED/HIGH RAD FAN RELAY

Does the test light illuminate brightly and flash on and off?

Yes

Replace the Med/High Rad Fan Relay.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

4.SERIES/PARALLEL RAD FAN RELAY)

Does the test light illuminate brightly and flash on and off?

Yes

Replace the Series/Parallel Rad Fan Relay.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

5.(N112) RAD FAN RELAY CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE

Is there voltage present?

Yes

Repair the short to voltage in the (N112) Rad Fan Relay Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

6.(N112) RAD FAN RELAY CONTROL CIRCUIT OPEN

Is the resistance below 5.0 ohms?

Yes

Repair the open in the (N112) Rad Fan Relay Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

7.(N112) RAD FAN RELAY CONTROL CIRCUIT SHORTED TO GROUND

Is the resistance below 100 ohms?

Yes

Repair the short to ground in the (N112) Rad Fan Relay Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Replace the Totally Integrated Power Module in accordance with the Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)