For 1990-2009 cars

### 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 Descriptor

DTC P0480 00: Cooling Fan Relay 1 Control Circuit
DTC P0481 00: Cooling Fan Relay 2 Control Circuit
DTC P0482 00: Cooling Fan Relay 3 Control Circuit
DTC P0691 00: Cooling Fan Relay 1 Control Circuit Low Voltage
DTC P0692 00: Cooling Fan Relay 1 Control Circuit High Voltage
DTC P0693 00: Cooling Fan Relay 2 Control Circuit Low Voltage
DTC P0694 00: Cooling Fan Relay 2 Control Circuit High Voltage
DTC P0695 00: Cooling Fan Relay 3 Control Circuit Low Voltage
DTC P0696 00: Cooling Fan Relay 3 Control Circuit High Voltage

### Diagnostic Fault Information

#### KR20J Cooling Fan Left High Speed Relay

Circuit | Short to Ground | High Resistance | Open | Short to voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Relay Coil Ignition Circuit | P0691 00 | P0691 00 | P0480 00 | -- | --
Relay Switch B+ Circuit | 1 | 1 | 1 | -- | --
Relay Coil Control Circuit | P0691 00 | P0691 00 | P0480 00 | P0692 00 | --
Relay Controlled Output Circuit | 1 | 1 | 1 | 2 | --

1. Low and medium speed fan inoperative without a DTC.
2. Medium speed fan always ON without a DTC.

#### KR20G Cooling Fan Left Low Speed Relay, KR20E Cooling Fan Speed Control Relay and KR20H Cooling Fan Right Low Speed Relay

Circuit | Short to Ground | High Resistance | Open | Short to voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Relay Coil Ignition Circuit | P0693 00 | P0693 00 | P0481 00 | -- | --
Relay Switch B+ Circuit | 1 | 1 | 1 | -- | --
Relay Coil Control Circuit | P0693 00 | P0693 00 | P0481 00 | P0694 00 | --
Relay Controlled Output Circuit | 1 | 1 | 1 | 2 | --

1. Fans inoperative without a DTC.
2. Medium speed fan always ON without a DTC.

#### KR20A Cooling Fan Medium Speed Relay

Circuit | Short to Ground | High Resistance | Open | Short to voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Relay Coil Ignition Circuit | P0695 00 | P0695 00 | P0482 00 | -- | --
Relay Switch B+ Circuit | 1 | 1 | 1 | -- | --
Relay Coil Control Circuit | P0695 00 | P0695 00 | P0482 00 | P0696 00 | --
Relay Controlled Output Circuit | 1 | 1 | 1 | 2 | --

1. High speed fan inoperative without a DTC.
2. High speed fan always ON without a DTC.

### Circuit/System Description

The engine control module (ECM) commands the fan ON in either high speed, medium speed, or low speed, depending on cooling requirements. In low speed, the fan are turned ON at a reduced speed. In medium speed, the fans are turned ON at a higher reduced speed. In high speed, the fans are turned ON at full speed. In low speed operation, the ECM provides ground to ECM terminal 94 (X2). The cooling fan relay activates and provides ground to the coil of the cooling fan left high speed relay. The cooling fan speed control relay remains inactive because ECM terminal 90 (X2) is not grounded. The cooling fan left high speed relay provides power to the engine cooling fan-right through engine cooling fan-left and the internal fan resistor of engine cooling fan-right.

In medium speed operation, the ECM provides ground to ECM terminal 90 (X2). The cooling fan left low speed, cooling fan speed control relay and the cooling fan right low speed relay are activated. The internal fan resistor of the engine cooling fan-left is provided with power through the cooling fan left low speed relay. The cooling fan speed control relay is active an d therefore the engine cooling fan-left terminal 3 is directly shorted to ground. The cooling fan right low speed relay is active and provides power to the internal resistor of the engine cooling fan-right. The engine cooling fan-right terminal 3 is directly shorted to ground. Both fans runs with medium speed.

In high speed operation, the ECM provides ground to ECM terminals 90 (X2), 91 (X2) and 94 (X2). Cooling fan left high speed relay, cooling fan medium speed 1 relay, cooling fan left low speed relay, cooling fan speed control relay and cooling fan right low speed relay are activated. Power is now provided to both cooling fan terminals 1. The engine cooling fan relay-left is directly shorted to ground through the cooling fan speed control relay. The engine cooling fan-right is directly shorted to ground. In this constellation both fans run without resistor.

### Conditions for Running the DTC

• | The ignition voltage is between 8-18 V.

• | The engine is running greater than or equal to 400 RPM.

### Conditions for Setting the DTC

#### P0480 00

The ECM detects a malfunction on the cooling fan relay 1 control circuit.

#### P0481 00

The ECM detects a malfunction on the cooling fan relay 2 control circuit.

#### P0482 00

The ECM detects a malfunction on the cooling fan relay 3 control circuit.

#### P0691 00

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

#### P0692 00

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

#### P0693 00

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

#### P0694 00

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

#### P0695 00

The ECM detects a short to ground on the cooling fan relay 3 control circuit.

#### P0696 00

The ECM detects a short to voltage on the cooling fan relay 3 control circuit.

### Action Taken When the DTC Sets

DTCs P0691 00, P0692 00, P0693 00, P0694 00, P0695 00 and P0696 00 are Type B DTCs.

### Conditions for Clearing the DTC

DTCs P0691 00, P0692 00, P0693 00, P0694 00, P0695 00 and P0696 00 are Type B DTCs.

### Reference Information

#### Schematic Reference

Engine Cooling Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Cooling Fan Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | 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

1. Command the Cooling Fan Relay 1 ON and OFF with a scan tool. The clicking sound of the relay should be heard when changing between the commanded states.

⇒ | If the relay does not operate correctly, refer to P0480 00, P0691 00 and P0692 00.

2. Command the Cooling Fan Relay 2 ON and OFF with a scan tool. The clicking sound of the relay should be heard when changing between the commanded states.

⇒ | If the relay does not operate correctly, refer to P0481 00, P0693 00 and P0694 00.

3. Command the Cooling Fan Relay 3 ON and OFF with a scan tool. The clicking sound of the relay should be heard when changing between the commanded states.

⇒ | If the relay does not operate correctly, refer to P0482 00, P0695 00 and P0696 00.

### Circuit/System Testing

#### P0480 00, P0691 00 and P0692 00

1. Ignition OFF, disconnect the KR20J Cooling Fan Left High Speed Relay.
2. Ignition ON, verify that a test lamp does not illuminate between the relay coil control circuit terminal and ground.

⇒ | If the test lamp illuminates, test the relay coil control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

3. Ignition OFF, disconnect the K20 Engine Control Module (ECM). Test for an infinite resistance between the relay coil control circuit terminal and ground.

⇒ | If less than the specified value, test the relay coil control circuit for a short to ground.

4. Test for less than 5.0 Ω between relay coil control circuit terminal and K20 Engine Control Module (ECM) terminal 94 (X2).

⇒ | If greater than the specified value, test the relay coil control circuit for an open/high resistance.

5. Test for 70-110 Ω between terminals 85 and 86 of the KR20J Cooling Fan Left High Speed Relay.

⇒ | If the resistance is not within the specified range, replace the KR20J Cooling Fan Left High Speed Relay.

#### P0481 00, P0693 00 and P0694 00

1. Ignition OFF, disconnect the KR20G Cooling Fan Left Low Speed Relay.
2. Ignition ON, verify that a test lamp does not illuminate between the relay coil control circuit terminal and ground.

⇒ | If the test lamp illuminates, test the relay coil control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

3. Ignition OFF, disconnect the K20 Engine Control Module (ECM). Test for an infinite resistance between the relay coil control circuit terminal and ground.

⇒ | If less than the specified value, test the relay coil control circuit for a short to ground.

4. Test for less than 5.0 Ω between relay coil control circuit terminal and K20 Engine Control Module (ECM) terminal 94 (X2).

⇒ | If greater than the specified value, test the relay coil control circuit for an open/high resistance.

5. Test for 70-110 Ω between terminals 85 and 86 of the KR20G Cooling Fan Left Low Speed Relay.

⇒ | If the resistance is not within the specified range, replace the KR20G Cooling Fan Left Low Speed Relay.

#### P0482 00, P0695 00 and P0696 00

1. Ignition OFF, disconnect the KR20A Cooling Fan Medium Speed Relay.
2. Ignition ON, verify that a test lamp does not illuminate between the relay coil control circuit terminal and ground.

⇒ | If the test lamp illuminates, test the relay coil control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

3. Ignition OFF, disconnect the K20 Engine Control Module (ECM). Test for an infinite resistance between the relay coil control circuit terminal and ground.

⇒ | If less than the specified value, test the relay coil control circuit for a short to ground.

4. Test for less than 5.0 Ω between relay coil control circuit terminal and K20 Engine Control Module (ECM) terminal 94 (X2).

⇒ | If greater than the specified value, test the relay coil control circuit for an open/high resistance.

5. Test for 70-110 Ω between terminals 85 and 86 of the KR20A Cooling Fan Medium Speed Relay.

⇒ | If the resistance is not within the specified range, replace the KR20A Cooling Fan Medium Speed Relay.

### Component Testing

#### Dynamic Test

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

⇒ | 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

• | 30 and 86

⇒ | If not the specified value, replace the relay.

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

⇒ | If more than the specified value, replace the relay.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Relay Replacement

• | Control Module References for ECM replacement, setup, and programming

### Repair Verification

1. Ignition ON, verify with a scan tool that the ECM is not commanding fan activation.
2. Ignition ON, observe that the fan is not activated.

Ignition ON, verify with a scan tool that the ECM is not commanding fan activation. Ignition ON, observe that the fan is not activated.