Wiper System & Washer System Buick LaCrosse I

Fastener Tightening Specifications

Fastener Tightening Specifications

Scheme 1

Scheme 2

Wiper/Washer System Connector End Views

Windshield Washer Fluid Level Switch Connector Part Information OEM: 15449028 Service: See Catalog 2-Way F GT 150 Series Sealed (BK) Pin Wire Color Circuit No. Function A TN 185 Low Washer Fluid Indicator Signal B BK 1250 Ground

Windshield Washer Fluid Pump Connector Part Information OEM: 12185025 Service: 89046634 2-Way F Mini Timer Sealed (BK) Pin Wire Color Circuit No. Function 1 RD 228 Windshield Washer Pump Control 2 BK 1250 Ground

Windshield Wiper Motor Connector Part Information OEM: Assembly 15326631 Connector 15326627 PLR 15326628 Connector Seal 15326630 Service: 15306360 4-Way F GT 280 Series Sealed (BK) Pin Wire Color Circuit No. Function A YE 196 Windshield Wiper Motor Park Switch Signal B BK 1650 Ground C D-GN 95 Windshield Wiper Motor Low Speed D PU 92 Windshield Wiper Motor High Speed

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Wiper/Washer Systems

Begin wiper/washer system diagnosis with the Diagnostic System Check - Vehicle in Vehicle DTC Information. The Diagnostic System Check will provide the following information

1. The identification of the control modules which command the system.
2. The ability of the control modules to communicate through the serial data circuit.
3. The identification of any stored diagnostic trouble codes (DTCs) and their status.

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Scan Tool Output Controls

Scan Tool Output Controls

Scan Tool Data List

Scan Tool Data List

Scan Tool Data Definitions

Use the scan tool data display values and definitions information in order to assist in diagnosing vehicle malfunctions. Compare the vehicles actual scan tool data display with the typical data value in the table. Use the data in order to aid in understanding the nature of the concern when the vehicle data display does not match the typical data values. Refer to Scan Tool Data List .

The typical scan tool data values were taken from a known good vehicle under the following conditions

1. The ignition switch is in the ON position.
2. The windshield wiper/washer switch is OFF.

Circuit Description

The body control module (BCM) controls and monitors the windshield washer fluid pump control circuit. The BCM supplies battery positive voltage to the windshield washer fluid pump when commanded ON by the windshield wiper/washer switch. Ground is applied at all times from G100 to the windshield washer fluid pump.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC B3873 Front Washer Relay Circuit

Conditions for Running the DTC

1. The ignition is ON.
2. The ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

The BCM detects an short to ground in the windshield washer pump control circuit.

Action Taken When the DTC Sets

The BCM will not activate the output.

Conditions for Clearing the DTC

1. The DTC will clear on current status after the condition for setting the fault is corrected.
2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.
3. History and current DTCs can be cleared using a scan tool.

Diagnostic Aids

Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

DTC B3873

The body control module (BCM) controls and monitors the state of the wiper control circuit. When the windshield wiper switch is placed in to a low speed setting, a signal is applied to the BCM. The BCM then applies battery positive voltage to the coil side of the WIPER relay through the WIPER relay control circuit. This energizes the WIPER relay, allowing battery positive voltage from the WIPER/WS fuse through the switched side of the WIPER relay to the windshield wiper motor. Ground is applied at all times to the coil side of the WIPER relay and the windshield wiper motor form G200.

This diagnostic procedure supports the following DTC

DTC B3874 Wiper Low Speed Relay Circuit

1. The ignition is in the ON position.
2. The ignition voltage is between 9-16 volts.

The following conditions will cause the DTC to set

1. The BCM detects an short to battery positive voltage in the WIPER relay control circuit for over 1 second.
2. The BCM detects a short to ground or an open in the WIPER relay control circuit.

The BCM will not activate the output.

1. The DTC will clear on current status after the condition for setting the fault is corrected.
2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.
3. History and current DTCs can be cleared using a scan tool.

Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

DTC B3874

The body control module (BCM) controls and monitors the state of the wiper high speed relay control circuit. When the windshield wiper switch is placed in to a high speed setting, a signal is applied to the BCM through the windshield wiper switch high signal circuit. The BCM then applies battery positive voltage to the WIPER HI relay through the wiper high speed relay control circuit. This energizes the WIPER HI relay, allowing battery positive voltage to be applies from the WIPER/WS fuse, through the switched contacts of the WIPER relay and through the switched contracts of the WIPER HI relay to the windshield wiper motor. Ground is applied at all times to the coil side of the WIPER HI relay and to the windshield wiper motor from G200.

This diagnostic procedure supports the following DTC

DTC B3875 Wiper High Speed Relay Circuit

1. The ignition is in the ON position.
2. The ignition voltage is between 9-16 volts.

The following conditions will cause the DTC to set

1. The BCM detects an short to battery positive voltage in the wiper high speed relay control circuit for over 1 second.
2. The BCM detects an open or a short to ground in the wiper high speed relay control circuit for over 1 second.

The BCM will not activate the Wiper HI relay.

1. A current DTC B3875 will clear if the short to battery, a short to ground or an open in the wiper high speed relay control circuit is no longer detected by the BCM.
2. A history DTC B3875 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
3. The BCM receives a clear code command from the scan tool.

1. If the DTC B3875 is a history DTC, the fault may be intermittent. Refer to «Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing) in Wiring Systems.
2. The following conditions may cause an intermittent malfunction or occur: An intermittent short to battery, a short to ground or an open in the wiper high speed relay control circuit. The WIPER HI relay coil is intermittently shorted to battery. The BCM is intermittently shorted to battery, shorted to ground or an open.

DTC B3875

The body control module (BCM) monitors the windshield wiper switch low signal circuit. When the wiper switch is placed in a low position, a signal is applied to the BCM through the windshield wiper switch low signal circuit. The BCM then applies a battery positive voltage to the WIPER relay control circuit which energizes the WIPER relay, allowing the battery positive voltage from WIPER/WS fuse through the switched side of the WIPER relay to the windshield wiper motor.

This diagnostic procedure supports the following DTC

DTC B3922 Front Wiper Select Circuit

1. The ignition switch is in the ON position.
2. The ignition voltage is between 9-16 volts.

1. The BCM detects an short to battery positive voltage or a short to ground on the windshield wiper switch low signal circuit.
2. The BCM detects a short to ground in the windshield wiper motor park switch signal circuit.

The windshield wipers will only function in the high mode.

1. The DTC will clear on current status after the condition for setting the fault is corrected.
2. A history DTC will clear after 100 consecutive ignition cycles without a fault present.
3. History and current DTCs can be cleared using a scan tool.

Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections .

DTC B3922

Symptoms - Wiper/Washer Systems

Visual/Physical Inspection

1. Inspect the washer fluid reservoir for the proper fluid level and condition.
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Inspect for aftermarket devices which could affect the operation of the Windshield Wiper/Washer System.

Intermittent

1. If the wipers operate at low speed for approximately 3 seconds and then stop, the wiper motor park switch or its signal circuit, may be malfunctioning. Refer to «Wipers Inoperative - One or More Modes»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__wipers-inoperative-one-or-more) .
2. Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to «Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing) in Wiring Systems.

Symptom List

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

1. «Low Washer Fluid Indicator Malfunction»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__low-washer-fluid-indicator-malfunction)
2. «Washers Always On»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__washers-always-on)
3. «Washers Inoperative»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__washers-inoperative)
4. «Wipers Always On»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__wipers-always-on)
5. «Wipers Inoperative - All Modes»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__wipers-inoperative-all-modes)
6. «Wipers Inoperative - One or More Modes»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__wipers-inoperative-one-or-more)
7. «Wipers Blades Do Not Park»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__wipers-blades-do-not-park)

Low Washer Fluid Indicator Malfunction

Low Washer Fluid Indicator Malfunction

Washers Always On

Washers Always On

Washers Inoperative

Washers Inoperative

Wipers Always On

Wipers Always On

Wipers Inoperative - All Modes

Wipers Inoperative - All Modes

Wipers Inoperative - One or More Modes

Wipers Inoperative - One or More Modes

Wipers Blades Do Not Park

Wipers Blades Do Not Park

Wiper Arm Pressure Check

1. Remove the wiper blades from the wiper arms. Refer to «Wiper Arm Blade Replacement»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) .
2. Attach a scale to the end of the wiper arm and measure the force required to lift the wiper arm to the following dimensions: Driver side wiper arm 37.3 mm (1.5 in) off of the windshield. Passenger side wiper arm 10.5 mm (0.4 in) off of the windshield.
3. Replace the wiper arm if the measurement is not within the specification. Refer to «Wiper Arm Replacement»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) . Tip Pressure: 8-10 N (29-36 oz.)
4. Install the wiper blades on the wiper arms. Refer to «Wiper Arm Blade Replacement»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) .

Wiper Blade Element Check

1. Remove the wiper blades from the wiper arms. Refer to «Wiper Arm Blade Replacement»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) .
2. Look down the length of the blade element.
3. Replace the wiper blade element if the rubber element which contacts the glass is deflected more than 15 degrees from the centerline of the blade. Refer to «Wiper Blade Element Replacement»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) .
4. Install the wiper blades on the wiper arms. Refer to «Wiper Arm Blade Replacement»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) .

Scheme 3

Wiper Arm, Blade & Insert Replacement - Front

Scheme 4

Wiper Motor & Wiper System Module Replacement

Removal Procedure

1. Raise the hood.
2. Drain the washer solvent from the washer solvent container.
3. Remove the upper washer solvent container screw.
4. Remove the right front fender liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
5. Disconnect the washer pump hose.
6. Disconnect the washer pump electrical connector.
7. Disconnect the washer solvent level sensor electrical connector.
8. Remove the washer pump from the container.
9. Remove the level sensor from the container.
10. Remove the lower washer solvent container screws.
11. Remove the washer solvent container from the right frame rail.

Installation Procedure

1. Position the washer solvent container to the right frame rail.
2. Install the lower washer solvent container screws. Tighten: Tighten the screws to 10 N.m (89 lb in).
3. Install the washer pump to the container.
4. Install the level sensor to the container.
5. Connect the washer solvent level sensor electrical connector.
6. Connect the washer pump electrical connector.
7. Connect the washer pump hose.
8. Install the right front fender liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
9. Install the upper washer solvent container screw. Tighten: Tighten the screw to 10 N.m (89 lb in).
10. Fill the washer solvent container with washer solvent.
11. Close the hood.

1. Drain the washer solvent from the washer solvent container.
2. Remove the right front fender liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
3. Disconnect the washer solvent container level sensor electrical connector.
4. Using a small flat-bladed tool, remove the washer solvent level sensor from the washer solvent container.
5. Using a small flat-bladed tool, remove the seal from the washer solvent container.

1. Position the seal to the washer solvent container, pressing in until fully seated.
2. Position the washer solvent level sensor to the washer solvent container, pressing in until fully seated.
3. Connect the washer solvent level sensor electrical connector.
4. Install the right front fender liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
5. Fill the washer solvent container with washer solvent.

1. Open the hood.
2. Drain the washer solvent from the washer solvent container.
3. Remove the right front fender liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
4. Disconnect the washer pump electrical connector.
5. Disconnect the washer pump hose.
6. Use a small flat-bladed tool to remove the washer pump from the washer solvent container.
7. Use a small flat-bladed tool to remove the seal from the washer solvent container.

1. Install the seal to the washer solvent container.
2. Install the washer pump to the washer solvent container.
3. Connect the washer pump electrical connector.
4. Connect the washer pump hose.
5. Install the right front fender liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
6. Fill the washer solvent container with washer solvent.
7. Close the hood.

1. Open the hood.
2. Remove the right front fender liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
3. Disconnect the washer hose from the washer pump.
4. Lower the Vehicle.
5. Disconnect the washer hose from the wiper arms.
6. Disconnect the washer hose from the air inlet grille panel.
7. Pull the washer pump hose out from along side the right front inner fender and into the engine compartment.
8. Remove the washer hose from the vehicle.

1. Position the washer hose to the vehicle.
2. Route the washer pump hose down along side the right front inner fender and into the front inner fender area.
3. Connect the washer hose to the air inlet grille panel.
4. Connect the washer hose to the wiper arms.
5. Raise the vehicle.
6. Connect the washer hose to the washer pump.
7. Install the right front fender liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
8. Close the hood.

Tools Required

J 39822 Wiper Arm Puller. See Special Tools .

1. Ensure that the wipers are in the park position and the ignition key is OFF.
2. Open the hood.
3. Disconnect the washer hose from the wiper arm.
4. Remove the wiper arm nut cover.
5. Remove the wiper arm nut.
6. Use the J 39822 to remove the wiper arm from the wiper transmission. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__special-tools) .

1. Position the wiper arm onto the wiper transmission.
2. Align the wiper blades to the small voids in the windshield blackout (1 and 2).
3. Apply Threadlocking compound, GM P/N 89021297 (Canadian P/N 10953488) or equivalent, to the wiper arm nut.
4. Install the wiper arm nut. Tighten: Tighten the nut to 30 N.m (22 lb ft).
5. Install the wiper arm nut cover.
6. Connect the washer hose to the wiper arm.
7. Operate the windshield wipers and inspect for proper operation.
8. Close the hood.

1. Turn the ignition ON.
2. Turn the wiper switch to the DELAY position.
3. Turn the ignition OFF when the windshield wipers are in the midwipe position.
4. Press the wiper blade clip button in to release the wiper blade from the inside radius of the wiper arm.
5. Remove the wiper arm out through the opening in the wiper blade.

1. Install the hook of the wiper arm through the opening in the wiper blade.
2. Position the wiper blade pivot in the inside radius of the wiper arm hook.
3. Press the wiper blade pivot into the wiper arm hook until the pivot locks into the hook.
4. Operate the windshield wipers and inspect for proper operation.

1. Remove the wiper blade from the wiper arm. Refer to «Wiper Arm Blade Replacement»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) .
2. Remove the bottom claws (2) of the wiper blade (1) from the notches in the wiper blade element (3).
3. Pull the wiper blade element (3) out through the wiper blade claws (2).

1. Insert the open end of the wiper blade element (3) into the bottom claws of the wiper blade (2).
2. Guide the wiper blade element (3) through the wiper blade (1) claw sets.
3. Engage the bottom claw (2) of the wiper blade (1) into the notches in wiper blade element (3).
4. Install the wiper blade onto the wiper arm. Refer to «Wiper Arm Blade Replacement»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) .

1. J 39232 Wiper Transmission Separator
2. J 39529 Wiper Transmission Installer

1. Remove the air inlet grille panel. Refer to «Air Inlet Grille Panel Replacement»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
2. Disconnect the wiper transmission link from the wiper motor crank arm using the J 39232 .
3. Remove the wiper drive system module screws.
4. Rotate the wiper drive system module to access the wiper motor electrical connector.
5. Disconnect the wiper motor electrical connector.
6. Remove the wiper drive system module from the vehicle.

1. Position the wiper drive system module to the vehicle.
2. Connect the wiper motor electrical connector.
3. Rotate the wiper drive system module to the mounting position.
4. Install the wiper drive system module screws. Tighten: Tighten the screws to 10 N.m (89 lb in).
5. Install the wiper transmission link to the wiper motor crank arm using the J 39529 .
6. Install the air inlet grille panel. Refer to «Air Inlet Grille Panel Replacement»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
7. Inspect the wipers for proper operation.

1. Remove the wiper drive system module. Refer to «Wiper Drive System Module Replacement»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) .
2. Remove the wiper crank arm nut (2) from the wiper motor shaft.
3. Remove the wiper crank arm (1) from the wiper motor shaft.
4. Remove the wiper motor screws from the wiper motor.
5. Remove the wiper motor from the wiper module.

1. Position the wiper motor to the wiper drive system module.
2. Install the wiper motor screws. Tighten: Tighten the screws to 7 N.m (62 lb in).
3. Install the wiper crank arm (1) to the wiper motor shaft.
4. Install the wiper crank arm nut (2) to the wiper motor shaft. Tighten: Tighten the nut to 30 N.m (22 lb ft).
5. Install the wiper drive system module. Refer to «Wiper Drive System Module Replacement»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) .

1. J 39232 Wiper Transmission Separator. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__special-tools) .
2. J 39529 Wiper Transmission Installer. See «Special Tools»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__special-tools) .

1. Remove the air inlet grille panel. Refer to «Air Inlet Grille Panel Replacement»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
2. Using the J 39232 , disconnect the wiper transmission from the wiper motor crank arm.
3. Remove the wiper motor crank arm cover.
4. Remove the wiper motor crank arm screw.
5. Remove the wiper motor crank arm from the wiper motor.

1. Position the wiper motor crank arm onto the wiper motor.
2. Measure the gap between wiper motor crank arm and the bracket tab. If the gap is not 4-8 mm (0.157-0.314 in), remove the wiper motor crank arm and repeat installation.
3. Install the wiper motor crank arm screw. Tighten: Tighten the screw to 16 N.m (12 lb ft).
4. Install the wiper motor crank arm cover.
5. Using the J 39529 , install the wiper transmission to the wiper motor crank arm.
6. Install the air inlet grille panel. Refer to «Air Inlet Grille Panel Replacement»(/buick/lacrosse/i-2004-2009/remont/exterior-body-panels/#body-front-end) in Body Front End.
7. Operate the windshield wipers and inspect for proper operation.

Wiper Chatter Repair

Some vehicles may exhibit a condition where the windshield wipers chatter and/or wipe unevenly. Several items may contribute to this condition. To completely repair this condition, ALL of the items listed should be tested and repaired as necessary.

1. Clean the windshield glass. Refer to «Windshield Glass Cleaning»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__windshield-glass-cleaning) .
2. Clean the wiper blade elements. Refer to «Blade Element Cleaning»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__blade-element-cleaning) .
3. Perform the wiper arm tip pressure test. Refer to «Wiper Arm Tip Pressure Check»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system) .
4. Inspect the wiper blade element set. Refer to «Wiper Blade Element Check»(/buick/lacrosse/i-2004-2009/remont/wiperwasher-systems/#wiper-system-washer-system__wiper-blade-element-check) .

Windshield Glass Cleaning

Clean the windshield with windshield cleaner, GM P/N 1050011 (Canadian P/N 992727) or equivalent. The cleaner should not harm the paint finish or scratch the glass. The glass is clean when the water no longer beads, but sheets across the entire glass surface.

Blade Element Cleaning

Lift each blade assembly off of the windshield and clean the element with a cloth saturated with full strength washer solvent. Then rinse the blade assemblies with clear water.

1. Disable the SIR system. Refer to «SIR Disabling and Enabling Zone 3»(/buick/lacrosse/i-2004-2009/remont/airbag/#supplemental-inflatable-restraint-system) in SIR.
2. Remove the steering column trim covers. Refer to «Steering Column Trim Covers Replacement (Manual Tilt)»(/buick/lacrosse/i-2004-2009/remont/ignition-switchsteering-lock/#steering-wheel-steering-column) in Steering Wheel and Column.
3. Remove the steering column wiring harness tie straps (1,2).
4. Disconnect the module electrical connectors (2).
5. Open the wire harness shield (1) at the lower steering column and remove the wire harness (2).
6. Disconnect the electrical connectors (1,3) from the windshield wiper and washer switch.
7. Depress the locking tab (2) on the windshield wiper and washer switch (1) and remove the switch from the steering column.

1. Install the windshield wiper and washer switch (1) to the steering column.
2. Connect the electrical connectors (1,3) on the windshield wiper and washer switch.
3. Install the wire harness (2) to the wire harness shield (1) on the lower steering column.
4. Route and connect the electrical connector from the windshield wiper and washer switch.
5. Install the wiring harness tie straps (1,2).
6. Install the steering column trim covers. Refer to «Steering Column Trim Covers Replacement (Manual Tilt)»(/buick/lacrosse/i-2004-2009/remont/ignition-switchsteering-lock/#steering-wheel-steering-column) in Steering Wheel and Column.
7. Enable the SIR system. Refer to «SIR Disabling and Enabling Zone 3»(/buick/lacrosse/i-2004-2009/remont/airbag/#supplemental-inflatable-restraint-system) in SIR.

Wiper/Washer System Components

The Wiper/Washer System consists of the following components

1. Windshield wiper/washer switch
2. Body control module (BCM)
3. WIPER relay
4. WIPER HI relay
5. Windshield wiper motor
6. Windshield washer fluid level switch
7. Windshield washer pump
8. WIPER/WS 25A fuse
9. WASHER/RVC 15A fuse

Wiper/Washer System Operation

The body control module (BCM) is part of the windshield wiper motor system and controls the wiper motor operation. The windshield wiper motor is a 2 speed motor. Windshield wiper intermittent operation is a low speed wiper motor function with a variable delay interval between the wipe cycles. The intermittent interval is controlled through a series of resistors within the wiper/washer switch. During intermittent wiper operation the windshield wiper switch low signal circuit is at the same circuit used for LOW operation.

Wiper/Washer System Description

Battery positive voltage is applied from the WIPER/WS fuse to the switch side of the WIPER relay. Battery positive voltage is also applied from the body control module (BCM) to the WIPER and WIPER HIGH relay coil circuits when commanded by the wiper switch.

Ground is applied continuously from G200 to windshield wiper motor and to the coil sides of the WIPER and WIPER HI relays. The BCM also provides a ground to the windshield wiper/washer switch.

Low Speed Operation

With the wiper switch in the low position, the body control module (BCM) detects a signal in the windshield wiper switch low signal circuit. The BCM then applies voltage to the WIPER relay control circuit. This energizes the WIPER relay and allows voltage to be applied through the switched contacts of the of the WIPER relay to the normally open switched contacts of the WIPER HI relay. Voltage is then applied from the WIPER HI relay normally open contacts to the low control circuit of the windshield wiper motor.

High Speed Operation

With the wiper switch in the high position, the body control module (BCM) receives two signals, one from the windshield wiper switch low signal circuit and one from the windshield wiper switch high signal circuit. When the BCM detects these two signals, the BCM then applies voltage to the wiper high speed relay control circuit. This energizes the WIPER relay and allows voltage to be applied from the switched contacts of the WIPER relay to the high control circuit of the wiper motor.

Intermittent Operation

Windshield wiper delay operation is a low speed wiper motor function which a variable delay interval between the wiper motor cycles. The delay interval is determined by a series of resistors within the wiper/washer switch. During delay wiper operation, the windshield wiper switch low signal is reduced through the delay resistors. The body control module (BCM) monitors the signal circuit to determine the delay interval between the low speed wiper motor cycles. If the wiper switch is moved from a longer delay interval to a shorter delay interval, the BCM will command an immediate wipe cycle and reset the delay timer to the shorter delay interval.

Park Position Operation

Windshield wiper motor park operation is controlled by the body control module (BCM) using an input from the park switch within the wiper motor assembly. The BCM monitors the windshield wiper motor park switch circuit to determine if the windshield wiper blades are at the bottom of the windshield. The circuit will be pulled to ground by the wiper motor park switch while the windshield wiper motor is in operation. When the wiper switch is turned to the OFF position while the wiper motor is somewhere in mid-cycle, the BCM will continue to operate the motor until the wipers reach the park position. If the ignition is turned off while the wipers are in mid-cycle, the wipers will stop immediately where they are. The BCM will park the wipers the next time the ignition is cycled to the ON position. The BCM provides stall protection for the wiper motor by monitoring the park switch. If the park switch does not transition for 3 seconds while the wipers are in operation, the BCM will assume the at the wiper motor is stalled and will de-energize the WIPER relay until the wiper switch is cycled off an on again.

Mist Operation

Windshield wiper/washer system MIST operation is identical to LOW operation, except that the MIST switch is a press and release type switch. When the wiper switch is moved to the MIST position and released, low speed wiper motor operation is started and will continue until 1 cycle is complete. If the wiper switch is moved to the MIST position and held, the wiper motor will operate in the LOW mode until the switch is released. In the MIST position, ground is supplied through an internal resistor to the windshield wiper switch low signal circuit to the body control module (BCM). The BCM will energize the WIPER relay that operates the windshield wiper motor at low speed.

Washer Operation

In the WASH position the windshield wiper/washer switch supplies a ground signal to the body control module (BCM) through the windshield washer switch signal circuit. The BCM will energize the WIPER relay that operates the windshield wiper motor at low speed and the BCM then applies voltage to the windshield washer fluid pump. The washer pump will function for as long as the washer switch is applied. The wiper motor will continue to operate for approximately 2 wipe cycles after the wash switch is released.

Low Washer Fluid Indicator

The low washer fluid indicator is located in the instrument panel cluster (IPC). Ground is applied at all times from G100 through the windshield washer fluid level switch, to the low washer fluid indicator signal circuit to the body control module (BCM). When the washer fluid is low, ground is removed from the low washer fluid indicator signal circuit to the BCM. The BCM then applies a message along the class 2 serial data circuit to the IPC. The IPC then illuminates the low washer fluid indicator.

Special Tools

Special Tools Illustration Tool Number/Description J 39232 Wiper Linkage Separator J 39529 Wiper Linkage Installer J 39822 Wiper Arm Puller

Scheme 5

See also:
• Diagnostic System Check - Vehicle
• Testing for Intermittent Conditions and Poor Connections
• Master Electrical Component List
• Circuit Testing
• Wiring Repairs
• Control Module References
• Connector Repairs
• Fastener Notice
• Fastener Tightening Specifications
• Air Inlet Grille Panel Replacement
• SIR Caution
• SIR Disabling and Enabling Zone 3
• Steering Column Trim Covers Replacement (Manual Tilt)
• DTC B3873
• Scan Tool Data List
• Wipers Inoperative - One or More Modes
• Low Washer Fluid Indicator Malfunction
• Washers Always On
• Washers Inoperative
• Wipers Always On
• Wipers Inoperative - All Modes
• Wipers Blades Do Not Park
• Wiper/Washer System Connector End Views
• Diagnostic Starting Point - Wiper/Washer Systems
• Special Tools
• Windshield Glass Cleaning
• Blade Element Cleaning
• Wiper Blade Element Check