Captiva

DTC P0480 or P0481 - LNP

The engine cooling fan system consists of a cooling fan assembly containing two electric cooling fans. The engine control module (ECM) uses two fan control circuits and a series of three relays to command the fans ON in either high speed or low speed, depending on cooling requirements. In low speed, both fans are turned ON at a reduced speed. High speed has both fans turned ON at full speed.

P0480

The commanded state of the ECM driver and the actual state of the control circuit do not match for greater than 5 seconds.

P0481

The commanded state of the ECM driver and the actual state of the control circuit do not match for greater than 5 seconds.

DTCs P0480 and P0481 are Type B DTCs.

DTCs P0480 and P0481 are Type B DTCs.

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Cooling Fan Description and Operation : LNP or LNQ

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Engine operating, observe the DTC information with a scan tool. DTC P0480 or P0481 should not set.
2. Command the cooling fans ON and OFF at high speed while observing the scan tool circuit test status parameters listed below:

•	Cooling Fan Relay 1 Control Circuit Open, Low Voltage, and High Voltage Test Status

•	Cooling Fan Relays 2 and 3 Control Circuit Open, Low Voltage, and High Voltage Test Status

The parameters should display OK or Not Run in each of the commanded states.

3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect all of the KR20 cooling fan relays.

Note:  The following test must be performed on all three fan relay circuits.

2. Ignition ON, verify that a test lamp illuminates between ground and the relay coil ignition circuit terminal listed below:

•	KR20J cooling fan left high speed relay terminal 86

•	KR20K cooling fan right high speed relay terminal 86

•	KR20E cooling fan speed control relay terminal 86

⇒	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 ignition circuit and replace as necessary.

Note:  The following tests must be performed on all three fan relay control circuits.

3. Connect the red lead of the DMM to a control circuit terminal listed below. Connect the black lead to ground. Set the DMM on the diode setting. The DMM should display OL.

•	KR20J cooling fan left high speed relay terminal 85

•	KR20K cooling fan right high speed relay terminal 85

•	KR20E cooling fan speed control relay terminal 85

⇒	If less than the specified range, test the appropriate relay coil control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

Note:  The following tests must be performed on all three fan relay control circuits.

4. Command the cooling fan relay ON and OFF with a scan tool. The DMM should transition from OL when commanded OFF to less than 1 V when commanded ON.

⇒	If the circuit voltage does not correspond to the specified values, test the control circuit for an open/high resistance or a short to voltage. If the circuit tests normal, replace the K20 ECM.

5. If all circuits test normal, test or replace the appropriate KR20 relay.

1. Ignition OFF, disconnect the KR20 cooling fan relay.
2. Test for 70-110 Ω between terminals 85 and 86.

⇒	If not within the specified range, replace the KR20 cooling fan relay.

3. Measure the resistance between the terminals listed below. The DMM should display OL.

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If less than the specified range, replace the KR20 cooling fan relay.

4. Test for less than 2 Ω between terminals 30 and 87A.

⇒	If greater than the specified range, replace the KR20E cooling fan relay.

5. Connect a 20 A fused jumper wire between relay terminal 86 and B+. Connect a jumper wire between relay terminal 85 and ground. Test for less than 2 Ω between terminals 30 and 87.

⇒	If greater than the specified range, replace the KR20 cooling fan relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.