P0480

P0480-COOLING FAN 1 CONTROL CIRCUIT





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

Theory of Operation

The Powertrain Control Module (PCM) controls the Cooling Fan 1 (Low Speed) Relay by grounding the (N201) Low/High Rad Fan Relay Control circuit when it is determined that low 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 Low/High 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, select Radiator Cooling Fan Relay #1 Control State to actuate the Cooling Fan (Low/High).

Is the one Cooling Fan operating?

Yes

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

No

- Go To 2

2. (N201) LOW/HIGH RAD FAN CONTROL CIRCUIT
1. Turn the ignition on, engine not running.
2. With a scan tool, select Radiator Cooling Fan Relay 1 Control State, Toggle, to actuate the Cooling Fan (Low/High).
3. Using a 12-volt test light connected to battery voltage, probe the (N201) Low/High Rad Fan Control circuit in the Low/High Rad Relay terminal.

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

Yes

- Replace the Low/High Rad Fan Relay.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 3

3. (N201) LOW/HIGH RAD FAN CONTROL CIRCUIT OPEN
1. Measure the resistance of the (N201) Low/High Rad Fan Control circuit from the PCM C1 harness connector to the (N201) Low/High Rad Fan Control circuit in the Low/High Rad Relay terminal.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the open in the (N201) Low/High Rad Fan Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

4. (N201) LOW/HIGH RAD FAN CONTROL CIRCUIT SHORTED TO GROUND




1. Measure the resistance between ground and the (N201) Low/High Rad Fan Control circuit in the PCM C1 harness connector.

Is the resistance below 100 Ohms?

Yes

- Repair the short to ground in the (N201) Low/High Rad Fan 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.