DTC P0480 or P0481. Saturn VUE

For 1990-2009 cars only

Makes 🢒 Saturn 🢒 2009 🢒 VUE - FWD 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC P0480 or P0481

DTC P0480 or P0481 LAT

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0480: Low Speed Cooling Fan Relay Control Circuit

DTC P0481: High Speed Cooling Fan Relay Control Circuit

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fan Main Relay Control Circuit	P0480	P0480	P0480	--
Fan Main Relay Coil Voltage Supply Circuit	P0480	P0480	P0480	--
Fan AUX Relay Control Circuit	P0481	P0481	P0481	--
Fan AUX Relay Coil Voltage Supply Circuit	P0481	P0481	P0481	--

The engine control module (ECM) grounds the fan AUX relay and the fan main relay control circuits through an internal solid state device called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line that is monitored by the ECM. When the ECM is commanding a component ON, the voltage potential of the control circuit should be low, near 0 volts. When the ECM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be high, near battery voltage. If the ECM detects that the actual state of the control circuit does not match the expected state, a DTC will set.

Conditions for Running the DTC

•	The engine is running.

•	The system voltage is between 11-18 volts.

Conditions for Setting the DTC

•	An improper voltage level has been detected on the cooling fan relay control circuit.

•	The condition must be present for a minimum of 30 seconds.

Action Taken When the DTC Sets

DTCs P0480 and P0481 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0480 and P0481 are Type B DTCs.

Reference Information

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Electrical Center Identification Views

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Verify cooling fan operation using the scan tool commands listed below:

•	Fan Relay 1 ON and Fan Relay 3 OFF--Fan runs at high speed.

•	Fan Relay 1 OFF and Fan Relay 3 ON--Fan runs at low speed.

Circuit/System Testing

Ignition OFF, disconnect the affected relay.
Verify that a test lamp illuminates between the B+ circuit terminal 85 and ground:

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test the control circuit terminal 87 for a short to ground. If the circuit tests normal, replace the relay.

Test for 70-110 ohms between terminal 85 and terminal 86 of the relay.

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

Test for 0.0A with a DMM connected in series with the relay coil between circuit terminal 85 and circuit terminal 86 at the relay connector.

⇒	If more than the specified value, test the control circuit terminal 86 for a short to ground. If the circuit tests normal, replace the ECM.

Command the relay ON with a scan tool. Verify that the DMM indicates more than 100 mA.

⇒	If not the specified range, test the control circuit terminal 86 for an open/high resistance. If the circuit tests normal, replace the ECM.

If all circuits and the ECM test normal, replace the affected relay.

Repair Instructions

Cooling Fan and Shroud Replacement

Repair Verification

Ignition ON, command the relay ON and OFF with a scan tool. Feel or listen to verify that the relay turns ON and OFF with each command.

DTC P0480 or P0481 LE5

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0480: Low Speed Cooling Fan Relay Control Circuit

DTC P0481: High Speed Cooling Fan Relay Control Circuit

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Low Speed Cooling Fan Relay Control Circuit	P0480	P0480	P0480	--
Low Speed Cooling Fan Relay Coil Voltage Supply Circuit	P0480	P0480	P0480	--
High Speed Cooling Fan Relay Control Circuit	P0481	P0481	P0481	--
High Speed Cooling Fan Relay Coil Voltage Supply Circuit	P0481	P0481	P0481	--

Circuit/System Description

The engine control module (ECM) commands the fans ON in high speed or low speed. In low speed, the fans are configured in series. In high speed, the fans are configured in parallel.

In low speed operation, the ECM applies ground to the coil side of fan relay. Voltage is applied directly to the left cooling fan through the switch side of fan AUX relay 3. The right fan is connected in series to the left fan through the de-energized FAN CTRL relay so that both fans operate at low speed.

In high speed operation, the ECM applies a ground to the coil side of fan AUX relay, FAN CTRL relay, and fan main relay. Voltage is applied directly to the right cooling fan through the switch side of fan main relay. The left cooling fan obtains voltage through fan AUX relay and ground through FAN CTRL relay 2.

When the ECM is commanding a fan relay ON, the voltage of the control circuit should be low, near 0 volts. When the ECM is commanding a fan relay OFF, the voltage of the control circuit should be high, near battery voltage.