GPEC

P0481-COOLING FAN 2 CONTROL CIRCUIT





For a complete wiring diagram Consult Diagrams/Electrical.

- 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.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.

Diagnostic Test

1. RADIATOR COOLING FAN MODULE OPERATION
Ignition on, engine not running.
With a scan tool, actuate both the Radiator Cooling Fan Relays #1 and #2.
Are both cooling fan operating at medium speed?

Yes

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Checking For An Intermittent DTC
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go to 2

2. (A16) FUSED B+ CIRCUIT




Ignition on.
Disconnect the Med/High Rad Fan Relay from the Fuse/Relay Block.
Disconnect the Series/Parallel Rad Fan Relay from the Fuse/Relay Block.
Using a 12-volt test light connected to ground, probe the (A16) Fused B+ circuit at both the Med/High Rad Fan Relay and the Series/Parallel Rad Fan Relay connectors.
Does the test light illuminate brightly at each terminal?

Yes

- Go to 3

No

- Repair the (A16) Fused B+ circuit. Inspect the related fuse and repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

3. MED/HIGH RAD FAN RELAY




Install the Series/Parallel Rad Fan Relay.
Turn the ignition on, engine not running.
With a scan tool, select Radiator Cooling Fan Relay #2 Control State, Toggle, to actuate the Cooling Fan (Med/High Rad Fan Relay).
Using a 12-volt test light connected to battery voltage, probe the (N112) Rad Fan Relay Control circuit at the 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. Powertrain Verification Test

No

- Go to 4

4. SERIES/PARALLEL RAD FAN RELAY




Remove the Series/Parallel Rad Fan Relay.
Install the Med/High Rad Fan Relay.
Turn the ignition on, engine not running.
With a scan tool, select Radiator Cooling Fan Relay #2 Control State, Toggle, to actuate the Cooling Fan (Series/Parallel Rad Fan Relay).
Using a 12-volt test light connected to battery voltage, probe the (N112) Rad Fan Relay Control circuit at the 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. Powertrain Verification Test

No

- Go to 5

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




Disconnect the TIPM C11 harness connector.
Using a voltmeter, measure the voltage of the (N112) Rad Fan Relay Control circuit in the Med/High Rad Fan Relay harness connector.
Is there voltage present?

Yes

- Repair the short to voltage in the (N112) Rad Fan Relay Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go to 6

6. (N112) RAD FAN RELAY CONTROL CIRCUIT OPEN




Measure the resistance of the (N112) Rad Fan Relay Control circuit from the Med/High Rad Fan Relay harness connector to the TIPM C11 harness connector.
Is the resistance below 5.0 ohms?

Yes

- Go to 7

No

- Repair the open in the (N112) Rad Fan Relay Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

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




Measure the resistance between ground and the (N112) Rad Fan Relay Control circuit in the TIPM C11 harness connector.
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. Powertrain Verification Test

No

- Replace the Totally Integrated Power Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test