• 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.

For symptom byte information, refer to Symptom Byte List.

The windshield wiper motor is controlled by the body control module (BCM) through the windshield wiper relay and the windshield wiper speed control relay. When low speed windshield wiper operation is requested, the BCM will apply voltage to the windshield wiper relay control circuit. This will cause the contacts in the windshield wiper relay to close and apply B+ to the windshield wiper motor through the windshield wiper low speed control circuit, enabling low speed wiper operation. When high speed windshield wiper operation is requested, the BCM continues to apply voltage to the windshield wiper relay control circuit and also applies ground to the windshield wiper speed control relay control circuit. This will cause the contacts in the windshield wiper speed control relay to close and apply B+ to the windshield wiper motor through the windshield wiper high speed control circuit, enabling high speed wiper operation. When the windshield wiper request is no longer present. the BCM uses an algorithm to keep relays engaged to keep wiper motor going at the last required speed until it sees that the motor is in the park position and then it will remove the necessary control drivers to stop the motor.

• The DTC runs only when a wiper output is actively being requested by the BCM.
• The system voltage is between 9–16 V.

A short to voltage is detected in the windshield wiper relay control circuit.

A short to ground is detected in the windshield wiper relay control circuit.

An open or high resistance is detected in the windshield wiper relay control circuit.

A short to voltage is detected in the windshield wiper high speed relay control circuit.

A short to ground is detected in the windshield wiper high speed relay control circuit.

An open or high resistance is detected in the windshield wiper high speed relay control circuit.

The BCM will not activate the wiper output.

• A current DTC will clear when the condition for setting the fault is no longer present.
• A history DTC will clear after 50 consecutive ignition cycles without a fault present.

Wiper/Washer Schematics

Master Electrical Component List

Wiper/Washer System Description and Operation

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Control Module References for scan tool information

1. Ignition OFF and all vehicle systems OFF, disconnect the KR12B Windshield Wiper Relay. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 Ω between the ground circuit terminal 2 and ground.
• If 10 Ω or greater
1. Ignition OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
• If 2 Ω or greater, repair the open/high resistance in the circuit.
• If less than 2 Ω, repair the open/high resistance in the ground connection.
• If less than 10 Ω
3. Ignition ON. Connect a test lamp between the control circuit terminal 1 and the ground circuit terminal 2.
4. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper Motor Relay On and Off with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, remove the test lamp, and disconnect the X4 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the control circuit terminal 16 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Ω in the control circuit end to end.
• If 2 Ω or greater, repair the open/high resistance in the circuit.
• If less than 2 Ω, replace the K9 Body Control Module.
• If the test lamp is always ON
1. Ignition OFF, remove the test lamp, and disconnect the X4 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the control circuit 16 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 Body Control Module.
• If the test lamp turns ON and OFF
5. Test or replace the KR12B Windshield Wiper Relay.

1. Ignition OFF, disconnect the KR12C Windshield Wiper Speed Control Relay, ignition ON.
2. Verify a test lamp Illuminates between the B+ circuit terminal 2 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF, remove the test lamp.
2. Test for less than 2 Ω in the B+ circuit terminal 2 circuit end to end.
• If 2 Ω or greater, repair the open/high resistance in the circuit.
• If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF, remove the test lamp.
2. Test for infinite resistance between the B+ circuit terminal 2 circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance,
3. Test for greater than 2 Ω between the control circuit terminal 1 and ground.
• If less than 2 Ω, repair the short to ground on the circuit.
• If greater than 2 Ω, test or replace the KR12C Windshield Wiper Speed Control Relay.
• If the test lamp illuminates
3. Connect a test lamp between the control circuit terminal 1 and the B+ circuit terminal 2.
4. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper Motor Relay High and Stop with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, remove the test lamp, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the control circuit terminal 24 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Ignition OFF.
4. Test for less than 2 Ω in the control circuit end to end.
• If 2 Ω or greater, repair the open/high resistance in the circuit.
• If less than 2 Ω, replace the K9 Body Control Module.
• If the test lamp is always ON
1. Ignition OFF, remove the test lamp, disconnect the X5 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the control circuit terminal 24 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K9 Body Control Module.
• If the test lamp turns ON and OFF
5. Test or replace the KR12C Windshield Wiper Speed Control Relay.

1. Ignition OFF, disconnect the appropriate relay.
2. Test for 60–200 Ω between terminals 1 and 2.
• If less than 60 or greater than 200

  Replace the relay.

• If between 60–200 Ω
3. Test for infinite resistance between the terminals listed below:
• 3 and 2
• 3 and 5
• 3 and 2
• 2 and 5
• If less than infinite resistance

  Replace the relay.

• If infinite resistance
4. Test for less than 5 Ω between terminals 3 and 4.
• If 5 Ω or greater

  Replace the relay.

• If less than 5 Ω
5. Install a 10 A fused jumper wire between relay terminal 1 and 12 V. Install a jumper wire between relay terminal 2 and ground.
6. Test for less than 5 Ω between terminals 3 and 5.
• If 5 Ω or greater

  Replace the relay.

• If less than 5 Ω
7. All OK

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• Electrical Relay Replacement
• Control Module References for body control module replacement, programming and setup.