Buick Regal: Symptoms - Wiper/Washer Systems

NOTE: The following steps must be completed before using the symptom tables:

1. Perform Diagnostic System Check - Vehicle , in order to verify that all of the following conditions are true:

• No DTCs are set.
• The control modules can communicate via the serial data link.

2. Refer to Wiper/Washer System Description and Operation in order to familiarize yourself with the system functions.

Visual/Physical Inspection

• Inspect for aftermarket devices which may affect the operation of the windshield wiper/washer system. Refer to Checking Aftermarket Accessories.
• Inspect the easily accessible or visible system components for obvious damage or conditions which may cause the symptom.
• Inspect the washer fluid reservoir for the proper fluid level.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

• Windshield Wiper System Malfunction
• Washer Malfunction
• Rain Sensor Malfunction

WINDSHIELD WIPER SYSTEM 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. Delay or Low Speed Wipers Inoperative
2. High Speed Wipers Inoperative
3. Wipers Do Not Park
4. Wipers Always ON

Circuit/System Description

The windshield wiper motor is controlled by the body control module (BCM) through the removable windshield wiper in conjunction with the removable 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 contacts in the windshield wiper relay and windshield wiper speed control relay will open, removing B+ from the wiper motor control circuits.

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 scan tool Windshield Wiper High Speed Switch parameter changes between Active and Inactive when activating the high speed windshield wipers.

• If the parameter does not change

Refer to Circuit/System Testing - Windshield Wiper/Washer Switch Malfunction.

• Go to next step: If the parameter changes

3. Verify the scan tool Windshield Wiper Switch parameter changes between Off and Low when activating the low speed windshield wipers.

• If the parameter does not change

Refer to Circuit/System Testing - Windshield Wiper/Washer Switch Malfunction.

• Go to next step: If the parameter changes

4. Verify the scan tool Windshield Wiper Switch parameter changes between Delay 1 and Delay 5 when cycling the intermittent speed windshield wipers.

• If the parameter does not change

Test or replace the S82 Windshield Wiper/Washer Switch.

• Go to next step: If the parameter changes

5. Verify the M75 Windshield Wiper Motor changes between Off, Low, and High when cycling the S82 Windshield Wiper/Washer Switch between Off, Low, and High.

• If the M75 Windshield Wiper Motor does not cycle between Off, Low, and High

Refer to Circuit/System Testing - Windshield Wiper Motor Malfunction

• Go to next step: If the M75 Windshield Wiper Motor cycles between Off, Low, and High

6. Ignition OFF.

7. Verify the scan tool Windshield Wiper Park Switch parameter is Active.

• If the parameter does not change

Refer to Circuit/System Testing - Windshield Wiper Motor Malfunction.

• Go to next step: If the parameter changes

8. All OK.

Circuit/System Testing

Windshield Wiper/Washer Switch Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S82 Windshield Wiper/Washer Switch. It may take up to 11 min for all vehicle systems to power down.

2. Test for less than 10 Ω between the low reference circuit terminal 1 and ground.

• If 10 Ω or greater

1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for less than 2 Ω in the low reference 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.

• Go to next step: If less than 10 Ω

3. Ignition ON.

4. Verify the scan tool Windshield Wiper High Speed Switch parameter is Inactive.

• If not Inactive

1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the signal circuit terminal 2 and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • If infinite resistance, replace the K9 Body Control Module.

• Go to next step: If Inactive

5. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1.

6. Verify the scan tool Windshield Wiper High Speed Switch parameter is Active.

• If not Active

1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • Go to next step: If less than 1 V
3. Test for less than 2 Ω in the signal 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.

• Go to next step: If Active

7. Test for greater than 8 V between the signal circuit terminal 3 and ground.

• If less than 8 V

1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the signal circuit 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 signal 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.

• Go to next step: If 8 V or greater

8. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module, ignition ON.

9. Test for less than 1 V between the S82 Windshield Wiper/Washer Switch signal circuit terminal 3 and ground.

• If 1 V or greater

Repair the short to voltage on the circuit.

• Go to next step: If less than 1 V

10. Test or replace the S82 Windshield Wiper/Washer Switch.

Windshield Wiper Motor Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the M75 Windshield Wiper Motor. 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 5 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.

• Go to next step: If less than 10 Ω

3. Ignition ON.

4. Verify the scan tool Windshield Wiper Park Switch parameter is Inactive.

• If not Inactive

1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the signal circuit terminal 3 and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • If infinite resistance, replace the K9 Body Control Module.

• Go to next step: If Inactive

5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 5.

6. Verify the scan tool Windshield Wiper Park Switch parameter is Active.

• If not Active

1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • Go to next step: If less than 1 V
3. Test for less than 2 Ω in the signal 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.

• Go to next step: If Active

7. 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.

8. Test for less than 10 Ω between the ground circuit terminals listed below and ground.

• terminal 85
• terminal 87A
• 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.

• Go to next step: If less than 10 Ω

9. Ignition ON.

10. Verify a test lamp illuminates between the B+ circuit terminal 87 and the ground circuit terminal 87A.

• 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 KR12C Windshield Wiper Speed Control Relay.
2. Test for infinite resistance between the control circuits listed below and ground.
   • Terminal 87A
   • Terminal 87
   • If less than infinite resistance, repair the short to ground on the circuit.
   • If infinite resistance, replace the M75 Windshield Wiper Motor

• Go to next step: If the test lamp illuminates

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

12. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper Motor Relay Low and Off with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the control circuit 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 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

13. Ignition OFF, connect the KR12B Windshield Wiper Relay and disconnect the KR12C Windshield Wiper Speed Control Relay, ignition ON.

14. Test for less than 10 Ω between the control circuit terminal 30 and ground.

• If 10 Ω or greater

Test or replace the KR12B Windshield Wiper Relay.

• Go to next step: If less than 10 Ω

15. Connect a test lamp between the control circuit terminal 30 and ground.

16. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper Motor Relay Low and Off with a scan tool.

• If the test lamp does not turn ON and OFF

Test or replace the KR12B Windshield Wiper Relay.

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

17. Verify a test lamp illuminates between the B+ circuit terminal 85 and ground.

• If the test lamp does not illuminate

Replace the X50A Fuse Block - Underhood.

• Go to next step: If the test lamp illuminates

18. Connect a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.

19. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper High Speed Relay High and Off with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, remove the test lamp, disconnect the 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.
   • Go to next step: 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 harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the control circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • If infinite resistance, replace the K9 Body Control Module.

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

20. Ignition OFF, connect the KR12C Windshield Wiper Speed Control Relay.

21. Connect a test lamp between the M75 Windshield Wiper Motor control circuit terminal 1 and ground circuit terminal 5, ignition ON.

22. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper Motor Relay Low and Off with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, remove the test lamp, disconnect the KR12C Windshield Wiper Speed Control Relay.
2. Test for infinite resistance between the control circuit 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, test or replace the KR12C Windshield Wiper Speed Control Relay.

• If the test lamp is always ON

1. Ignition OFF, remove the test lamp, disconnect the KR12C Windshield Wiper Speed Control Relay, 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, test or replace the KR12C Windshield Wiper Speed Control Relay.

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

23. Connect a test lamp between the M75 Windshield Wiper Motor control circuit terminal 4 and ground circuit terminal 5, ignition ON.

24. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper High Speed Relay High and Off with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, remove the test lamp, disconnect the KR12C Windshield Wiper Speed Control Relay.
2. Test for infinite resistance between the control circuit 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, test or replace the KR12C Windshield Wiper Speed Control Relay.

• If the test lamp is always ON

1. Ignition OFF, remove the test lamp, disconnect the KR12C Windshield Wiper Speed Control Relay, 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, test or replace the KR12C Windshield Wiper Speed Control Relay.

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

25. Test or replace the M75 Windshield Wiper Motor.

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 2 and the low reference terminal 1 with the high speed 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 2 and the low reference circuit terminal 1 with the high speed 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. Test for infinite resistance between the signal terminal 3 and the low reference terminal 1 with the low speed switch in the open position.

• If less than infinite resistance

Replace the S82 Windshield Wiper/Washer Switch.

• Go to next step: If infinite resistance

5. Test for the resistance values listed below between the signal circuit terminal 3 and the low reference circuit terminal 1 by cycling the switch between Delay 1 and Delay 5.

• Delay 1 : 3.8 kΩ
• Delay 2 : 2.8 kΩ
• Delay 3 : 1.9 kΩ
• Delay 4 : 2.8 kΩ
• Delay 5 : 770 Ω
• If not within the resistance values listed

Replace the S82 Windshield Wiper/Washer Switch.

• Go to next step: If within the resistance values listed

Relay Test

1. Ignition OFF, disconnect the appropriate relay.

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

• If less than 60 or greater than 200

Replace the 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 relay.

• Go to next step: If infinite resistance

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

• If 5 Ω or greater

Replace the relay.

• Go to next step: If less than 5 Ω

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

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

• If 5 Ω or greater

Replace the relay.

• Go to next step: If less than 5 Ω

7. All OK

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• Windshield Wiper Motor Replacement
• Relay Replacement (Attached to Wire Harness) Relay Replacement (Within an Electrical Center)
• Windshield Wiper and Washer Switch Replacement
• Control Module References for BCM replacement, setup, and programming

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