DTC P0480, P0481, P0691, P0692, P0693, or P0694 3.5L

Diagnostic Instructions

DTC Descriptors

DTC P0480: Cooling Fan Relay 1 Control Circuit

DTC P0481: Cooling Fan Relay 2 Control Circuit

DTC P0691: Cooling Fan Relay 1 Control Circuit Low Voltage

DTC P0692: Cooling Fan Relay 1 Control Circuit High Voltage

DTC P0693: Cooling Fan Relay 2 Control Circuit Low Voltage

DTC P0694: Cooling Fan Relay 2 Control Circuit High Voltage

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Relay Coil Ignition Circuit	P0691, P0693	P0480, P0481	--	--
Relay Switch Ignition Circuit	*	*	--	--
Fan Relay 1 Control Circuit	P0691	P0480	P0692	--
Fan Relay 2 Control Circuit	P0693	P0481	P0694	--
Relay Fan Supply Voltage Circuit	*	*	**	--
* Fans inoperative without a DTC. ** Fans always ON without a DTC.

Circuit/System Description

The Cooling Fan Relay 1 or the Fan Low Relay, and the Cooling Fan 2 or the Fan Hi Relay are controlled by the powertrain control module (PCM). Battery voltage is supplied to the cooling fan relay coil. The PCM monitors the voltage on the control circuit of the relay. When the relay is OFF, the voltage should be near battery voltage on the control circuit of the relay. When the relay is commanded ON, the voltage will be low on the control circuit of the relay. The PCM will provide ground on the control circuit of the relay using a low side driver.

Conditions for Running the DTC

Conditions for Setting the DTC

P0480

The PCM detects an open circuit on the cooling fan 1 relay control circuit.

P0481

The PCM detects an open circuit on the cooling fan 2 relay control circuit.

P0691

The PCM detects a short to ground on the cooling fan 1 relay control circuit.

P0692

The PCM detects a short to voltage on the cooling fan 1 relay control circuit.

P0693

The PCM detects a short to ground on the cooling fan 2 relay control circuit.

P0694

The PCM detects a short to voltage on the cooling fan 2 relay control circuit.

The PCM detects a short to voltage, a short to ground, or an open/high resistance on the cooling fan relay control circuits.

Action Taken When the DTC Sets

Conditions for Clearing the MIL/DTC

Diagnostic Aids

The following two tables illustrate the COOLING FAN 1 relay and the COOLING FAN 2 relay terminal locations in the underhood fuse block. The third table illustrates the COOLING FAN 3 relay terminal locations in the relay electrical connector.

COOL FAN 1 Relay

Terminal Identification
Cooling Fan Supply Voltage	B+ Coil
Control	B+ Switch
Front of Vehicle

COOL FAN 2 Relay

Terminal Identification
Cooling Fan Supply Voltage	B+ Coil
Control	B+ Switch
Front of Vehicle

COOLING FAN 3 Relay

Terminal Identification
B+ Coil	Voltage to Right Cooling Fan	Ground
Voltage from Left Cooling Fan	--	Control
Locking Tab

Reference Information

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

Cooling System Connector End Views

Description and Operation

Cooling System Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Circuit/System Verification

1. Ignition ON, command the appropriate cooling fan relay ON and OFF with a scan tool. Listen or feel for the relay to click.
2. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing

1. Ignition OFF, disconnect the appropriate cooling fan relay.
2. Ignition ON, verify that a test lamp illuminates between the relay coil ignition circuit and ground.

⇒	If the test lamp does not illuminate, test the relay coil ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the relay coil ignition circuit fuse is open, test all components connected to the relay coil ignition circuit and replace as necessary.

3. Connect a test lamp between the relay coil ignition circuit and the relay coil control circuit.
4. Command the cooling fan relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the relay coil control circuit for a short to ground. If the circuit tests normal, replace the PCM.

⇒	If the test lamp is always OFF, test the relay coil control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PCM.

5. If all circuits test normal, test or replace the appropriate cooling fan relay.

Component Testing

1. Ignition OFF, disconnect the appropriate cooling fan relay.
2. Test for 70-110 ohms of resistance between terminals 85 and 86.

⇒	If the resistance is not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If not the specified value, replace the relay.

⇒	If greater than the specified range, replace the relay.

4. Install a 20A fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms of resistance between terminals 30 and 87.

⇒	If greater than the specified range, replace the relay.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.