Buick Regal: Headlamp Washer Malfunction

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.

Diagnostic Fault Information

1. Headlamp Washer Inoperative
2. Headlamp Washers Always ON

Circuit/System Description

The headlamp washer pump is controlled by the body control module (BCM) via a removable relay. If the headlamp lights are on, the BCM will activate the headlamp washer pump the first time the windshield washer pump is activated. After the initial headlamp washer activation, the BCM will only allow headlamp washer function every 5 windshield washer cycles. When the headlamp washer function is requested by the BCM's internal logic, it applies voltage through a control circuit to the headlamp washer pump relay. With the relay energized, battery voltage is applied through the switch contacts of the relay and the fused control circuit to activate the headlamp washer pump.

Diagnostic Aids

The headlamp wash feature will only be activated if the low or high beam headlamps are active as well.

Reference Information

Schematic Reference

Wiper/Washer Wiring Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Wiper/Washer System Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify the headlamp washers turn ON and OFF when commanding the Headlamp Washer Relay Active and Inactive with a scan tool.

• If the Headlamp Washer Relay does not turn ON and OFF

Refer to Circuit/System Testing

• Go to next step: If the Headlamp Washer Relay turns ON and OFF

3. All OK.

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the KR2 Headlamp Washer Pump Relay. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 10 Ω between the ground circuit terminal 86 and ground.

• If 10 Ω or greater

1. 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.

• Go to next step: If less than 10 Ω

3. Ignition ON.

4. Verify a test lamp illuminates between the B+ circuit terminal 30 and ground.

• If the test lamp does not illuminate and the circuit fuse is good

Replace the X50A Fuse Block - Underhood.

• If the test lamp does not illuminate and the circuit fuse is open

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the G16 Headlamp Washer Pump.
2. Test for infinite resistance between the control circuit terminal 2 and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • If infinite resistance, replace the G16 Headlamp Washer Pump.

• Go to next step: If the test lamp illuminates

5. Connect a test lamp between the control circuit terminal 85 and the ground circuit terminal 86.

6. Verify the test lamp turns ON and OFF when commanding the Headlamp Washer Relay Active and Inactive 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.
2. Test for infinite resistance between the control circuit terminal 26 and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: 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, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the control circuit 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.

• Go to next step: If the test lamp turns ON and OFF

7. Verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.

• If the test lamp illuminates

Repair the short to voltage on the control circuit

• Go to next step: If the test lamp does not illuminate

8. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the G19 Headlamp Washer Pump. It may take up to 2 minutes for all vehicle systems to power down.

9. Test for less than 10 Ω between the ground circuit terminal 1 and ground.

• If 10 Ω or greater

1. 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.

• Go to next step: If less than 10 Ω

10. Connect the harness connector at the G19 Headlamp Washer Pump.

11. Ignition ON, connect a 15 A fused jumper wire between the control circuit terminal 87 and B+.

12. Verify the G19 Headlamp Washer Pump is activated.

• If the G19 Headlamp Washer Pump does not activate

1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the G19 Headlamp Washer Pump.
2. 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 G19 Headlamp Washer Pump.

• Go to next step: If the G19 Headlamp Washer Pump activates

13. Test or replace the KR2 Headlamp Washer Pump Relay.

Component Testing

Windshield Wiper/Washer Switch

1. Ignition OFF, disconnect the harness connector at the S82 Windshield Wiper/Washer Switch.

2. Test for infinite resistance between the signal terminal 5 and the low reference terminal 2 with the switch in the open position.

• If less than infinite resistance

Replace the S82 Windshield Wiper/Washer Switch.

• Go to next step: If infinite resistance

3. Test for less than 2 Ω between the signal circuit terminal 5 and the low reference circuit terminal 2 with the switch in the closed position.

• If 2 Ω or greater

Replace the S82 Windshield Wiper/Washer Switch.

• Go to next step: If less than 2 Ω

4. All OK

Relay Test

1. Ignition OFF, disconnect the KR2 headlamp washer pump relay.

2. Test for 60 - 200 Ω between terminals 85 and 86.

• If less than 60 or greater than 200

Replace the KR2 headlamp washer pump relay.

• Go to next step: If between 60 - 200 Ω

3. Test for infinite resistance between the terminals listed below:

• 30 and 86
• 30 and 87
• 30 and 85
• 85 and 87
• If less than infinite resistance

Replace the KR2 headlamp washer pump relay.

• Go to next step: If infinite resistance

4. Install a 10 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground.

5. Test for less than 10 Ω between terminals 30 and 87.

• If 10 Ω or greater

Replace the KR2 headlamp washer pump relay.

• Go to next step: If less than 10 Ω

6. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Relay Replacement (Attached to Wire Harness) Relay Replacement (Within an Electrical Center)
• Windshield Wiper and Washer Switch Replacement
• Engine Wiring Harness Junction Block Replacement (LTG) Engine Wiring Harness Junction Block Replacement (LGX)
• Control Module References for BCM replacement, programming and setup

READ NEXT: