P0481

P0481-COOLING FAN 2 CONTROL CIRCUIT

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Powertrain Control Module (PCM) controls the Cooling Fan 2 (High Speed) Relay by grounding the (N112) High Rad Fan Relay Control circuit when it is determined that high speed fan operation is required.

- 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. Pre-Diagnostic Troubleshooting Procedure.

1. RADIATOR COOLING FAN MODULE OPERATION
1. Ignition on, engine not running.
2. With a scan tool, actuate both the Radiator Cooling Fan Relays No.1 and No.2.

Are both cooling fan operating at medium speed?

Yes

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

No

- Go To 2

2. (N112) RAD FAN RELAY CONTROL CIRCUIT OPEN
1. Measure the resistance of the (N112) Rad Fan Relay Control circuit from the High Rad Fan Relay harness connector to the PCM C1 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 3

No

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

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




1. Measure the resistance between ground and the (N112) Rad Fan Relay Control circuit in the PCM C1 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 Powertrain Control Module (PCM). Powertrain Control Module - Removal
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.