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).
Diagnostic Test
1. RADIATOR COOLING FAN MODULE OPERATIONIgnition 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.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Replace the Totally Integrated Power Module in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)