FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Buick >> 2013 >> LaCrosse AWD V6-3.6L >> Repair and Diagnosis >> Wiper and Washer Systems >> Testing and Inspection >> Windshield Wiper System Malfunction

Windshield Wiper System Malfunction




Windshield Wiper System Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information






Circuit/System Description

The body control module (BCM) controls the wiper motor based on input from the windshield wiper/washer switch. The BCM monitors the wiper/washer switch through two separate signal circuits and a ground circuit. The windshield wiper switch high signal circuit is used to determine high speed wiper operation, the windshield wiper switch low signal is used to determine low speed, intermittent, and mist operation through the use of a resistor ladder, and the windshield washer switch signal circuit is used to determine washer operation.

The BCM controls the windshield wiper motor through two output controls, controlling two relays which determine the desired wiper speed, high or low.

Reference Information

Schematic Reference

Wiper/Washer Schematics Electrical Diagrams

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

Wiper/Washer System Description and Operation Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify the windshield wipers operate when commanding the Windshield Wipers ON with a scan tool.

• If Wipers Do Not Operate

1. Verify the solenoid in the relays listed below turn on and off/clicks when commanding the Windshield Wipers ON and OFF with a scan tool.

* KR12B Windshield Wiper Relay

* KR12C Windshield Wiper Speed Control Relay

• If the solenoid does not turn on and off/clicks, refer to Circuit/System Testing - Windshield Wiper Dual Relays Test.

• If the solenoid does turn on and off/clicks

2. Verify the scan tool Windshield Wiper Switch parameter changes between OFF, LOW, and HIGH while turning the wiper switch to the OFF, LOW, and HIGH positions.

• If the parameter does not change between OFF, LOW, and HIGH, refer to Circuit/System Testing - Windshield Wiper/Washer Switch Circuit Test.

• If the parameter does change between OFF, LOW, and HIGH, Refer to, refer to Circuit/System Testing - Windshield Wiper Motor Circuit Test.

• If Wipers Operate

3. Verify the scan tool Windshield Wiper Switch parameter changes between OFF, LOW, and HIGH while turning the wiper switch to the OFF, LOW, and HIGH positions.

• If the parameter does not change between OFF, LOW, and HIGH
Refer to Circuit/System Testing - Windshield Wiper/Washer Switch Circuit Test.

• If the parameter does change between OFF, LOW, and HIGH

4. Verify the scan tool Windshield Wiper Switch parameter cycles from Delay 1 through Delay 5 while cycling through the INT delay adjustment positions with the wiper switch.

• If the parameter does not change from Delay 1 through Delay 5
Replace the S82 windshield wiper/washer switch.

• If the parameter changes from Delay 1 through Delay 5

5. Verify the body control module Wiper Park Switch parameter is Active when the wipers are parked and Inactive when the wipers are ON or out of the park position.

• If the parameter is always Active or Inactive or the wipers do not park
Refer to Circuit/System Testing - Windshield Park Circuit Test.

• If the parameter changes between Active and Inactive and the wipers park

6. All OK.

Circuit/System Testing

Windshield Wiper/Washer Switch Circuit Test

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S82 windshield wiper/washer switch. It may take up to 2 minutes for all vehicle systems to power down.

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

• If 10 ohms or greater

1. Ignition OFF, disconnect the harness connector at the K9 body control module.

2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K9 body control module.

• If less than 10 ohms

3. Ignition ON.

4. Verify the scan tool Windshield Wiper Switch parameter is Off.

• If not Off

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.

• If Off

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

6. Verify the scan tool Windshield Wiper Switch parameter is On.

• If not On

1. Ignition OFF, 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.

• If less than 1 V

3. Test for less than 2 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K9 body control module.

• If On

7. 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 1 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 Inactive

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

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

• If not Active

1. Ignition OFF, 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.

• If less than 1 V

3. Test for less than 2 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K9 body control module.

• If Active

10. Test or replace the S82 windshield wiper/washer switch.

Windshield Wiper Motor Circuit Test

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the M75 Windshield Wiper Motor. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the ground circuit terminal 4 and ground.

• If 10 ohms or greater

1. Ignition OFF.

2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, repair the open/high resistance in the ground connection.

• If less than 10 ohms

3. Ignition ON.

4. Connect a test lamp between the control circuit terminal 5 and the ground circuit terminal 4.

5. Verify the test lamp turns ON and OFF when commanding the LOW speed wipers ON and OFF with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, 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

3. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, test or replace the KR12C windshield wiper speed control relay.

• If the test lamp is always ON

1. Ignition OFF, 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, test replace the KR12C windshield wiper speed control relay.

• If the test lamp turns ON and OFF

6. Connect a test lamp between the B+ circuit terminal 3 and the control circuit terminal 4.

7. Verify the test lamp turns ON and OFF when commanding the HIGH speed wipers ON and OFF with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, 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

3. Ignition OFF.

4. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, test or replace the KR12B windshield wiper relay.

• If the test lamp is always ON

1. Ignition OFF, 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, test or replace the KR12B windshield wiper relay.

• If the test lamp turns ON and OFF

8. Test or replace the M75 windshield wiper motor.

Wiper Park Circuit Test

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the M75 windshield wiper motor. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the ground circuit terminal 1 and ground.

• If 10 ohms or greater

1. Ignition OFF.

2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohmsor greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, repair the open/high resistance in the ground connection.

• If less than 10 ohms

3. Ignition ON.

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

• If not Active

1. Ignition OFF, disconnect the harness connector at the K9 body control module.

2. Test for infinite resistance between the signal circuit terminal 1 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 Active

5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 4.

6. 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, 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.

• If less than 1 V

3. Test for less than 2 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K9 body control module.

• If Inactive

7. Test or replace the M75 windshield wiper motor.

Windshield Wiper Dual Relays Test

1. Ignition OFF and all vehicle systems OFF, disconnect the KR12B Windshield Wiper Relay and the KR12C Windshield Wiper Speed Control Relay. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the ground circuits listed below and ground.

* Terminal 87A at the KR12B Windshield Wiper Relay

* Terminal 86 at the KR12C Windshield Wiper Speed Control Relay

• If 10 ohms or greater

1. Ignition OFF.

2. Test for less than 2 ohms in the ground circuits end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, repair the open/high resistance in the ground connection.

• If less than 10 ohms

3. Ignition ON.

4. Verify a test lamp illuminates between the B+ circuits listed below and ground.

* Terminal 87 at the KR12B Windshield Wiper Relay

* Terminal 85 at the KR12C Windshield Wiper Speed Control Relay

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

1. Ignition OFF.

2. Test for less than 2 ohms in the B+ circuits end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, 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.

2. Test for infinite resistance between the B+ circuits and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance

3. Test for infinite resistance between the B+ circuits and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, replace the X50A underhood fuse block.

• If the test lamp illuminates

5. Connect a test lamp between the control circuit terminal 86 and the ground circuit terminal 85 at the KR12B Windshield Wiper Relay.

6. Verify the test lamp turns ON and OFF when commanding the Windshield Wipers ON and OFF with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, disconnect the X4 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

3. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K9 Body Control Module.

• If the test lamp is always ON

1. Ignition OFF, disconnect the X4 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.

• If the test lamp turns ON and OFF

7. Connect a test lamp between the control circuit terminal 85 and the ground circuit terminal 86 at the KR12C Windshield Wiper Speed Control Relay.

8. Verify the test lamp turns ON and OFF when commanding the Windshield Wipers ON and OFF with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, 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 greater than 1 V, repair the short to voltage on the circuit.

• If less than 1 V

3. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K9 Body Control Module.

• If the test lamp is always ON

1. Ignition OFF, disconnect the X5 harness connector at the K9 Body Control Module, ignition ON.

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.

• If the test lamp turns ON and OFF

9. Ignition OFF, reconnect the KR12C Windshield Wiper Speed Control Relay and KR12B Windshield Wiper Relay.

10. Disconnect the X4 Harness connector at the K9 Body Control Module, ignition ON.

11. Connect a 3 A fused jumper wire between B+ and the control circuit terminal 16 at the KR12B Windshield Wiper Relay.

12. Verify the M75 Windshield Wiper Motor is activated.

• If the M75 Windshield Wiper Motor does not activate

1. Ignition OFF, disconnect the KR12C Windshield Wiper Speed Control Relay and KR12B Windshield Wiper Relay.

2. Test for less than 2 ohms in the control circuit between control circuit terminal 30 at the KR12C Windshield Wiper Speed Control Relay and the control circuit terminal 30 at the KR12B Windshield Wiper Relay.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms

3. Reconnect the KR12B Windshield Wiper Relay and the X4 harness connector at the K9 Body Control Module.

4. Connect a test lamp between the control circuit terminal 30 and the control circuit terminal 87 at the KR12C Windshield Wiper Speed Control Relay, ignition ON.

5. Verify the test lamp illuminates when commanding the Windshield Wipers ON.

• If test lamp does not illuminate, test or replace the KR12C Windshield Wiper Speed Control Relay.

• If test lamp illuminates, KR12B Windshield Wiper Relay.

• If the M75 Windshield Wiper Motor does activate

13. All OK.

Component Testing

Relay Test

1. Ignition OFF, disconnect the appropriate relay.

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

• If less than 60 or greater than 200
Replace the relay.

• If between 60-200 ohms

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.

• If infinite resistance

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

• If 5 ohms or greater
Replace the relay.

• If less than 5 ohms

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 ohms between terminals 30 and 87.

• If 5 ohms or greater
Replace the relay.

• If less than 5 ohms

7. All OK

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Windshield Wiper Motor Replacement Service and Repair

* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)

* Windshield Wiper and Washer Switch Replacement Service and Repair

* Control Module References Control Module References for BCM replacement, programming and setup

pro multis Credits:Operation CHARM About Operation CHARM