Wiper System & Washer System: Other Chevrolet Silverado 2500 HD

Reference Information

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Wiper/Washer Connector End Views

Electrical Information Reference

1. «Circuit Testing»(ref-278019-S01379251932008012100000)
2. «Connector Repairs»(ref-278019-S06982211772008012100000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-278019-S21810776732008012100000)
4. «Wiring Repairs»(ref-278019-S25320832652008012100000)

Scan Tool Reference

1. «Scan Tool Output Controls»(ref-278010-S25097610112008012100000)
2. «Scan Tool Data List»(ref-278010-S06165027152008012100000)
3. «Scan Tool Data Definitions»(ref-278010-S35031572712008012100000)

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Underhood Electrical Center or Junction Block Replacement»(ref-278007-S27290193332008012100000)
2. «Control Module References»(ref-278020-S09054666032008012100000) for BCM replacement, setup, and programming

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Wiper/Washer Connector End Views

Electrical Information Reference

1. «Circuit Testing»(ref-278019-S01379251932008012100000)
2. «Connector Repairs»(ref-278019-S06982211772008012100000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-278019-S21810776732008012100000)
4. «Wiring Repairs»(ref-278019-S25320832652008012100000)

Scan Tool Reference

1. «Scan Tool Output Controls»(ref-278010-S25097610112008012100000)
2. «Scan Tool Data List»(ref-278010-S06165027152008012100000)
3. «Scan Tool Data Definitions»(ref-278010-S35031572712008012100000)

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Underhood Electrical Center or Junction Block Replacement»(ref-278007-S27290193332008012100000)
2. «Control Module References»(ref-278020-S09054666032008012100000) for BCM replacement, programming, and setup

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Wiper/Washer Connector End Views

Electrical Information Reference

1. «Circuit Testing»(ref-278019-S01379251932008012100000)
2. «Connector Repairs»(ref-278019-S06982211772008012100000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-278019-S21810776732008012100000)
4. «Wiring Repairs»(ref-278019-S25320832652008012100000)

Scan Tool Reference

1. «Scan Tool Output Controls»(ref-278010-S25097610112008012100000)
2. «Scan Tool Data List»(ref-278010-S06165027152008012100000)
3. «Scan Tool Data Definitions»(ref-278010-S35031572712008012100000)

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Underhood Electrical Center or Junction Block Replacement»(ref-278007-S27290193332008012100000)
2. «Control Module References»(ref-278020-S09054666032008012100000) for BCM replacement, setup, and programming

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Wiper/Washer Connector End Views

Electrical Information Reference

1. «Circuit Testing»(ref-278019-S01379251932008012100000)
2. «Connector Repairs»(ref-278019-S06982211772008012100000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-278019-S21810776732008012100000)
4. «Wiring Repairs»(ref-278019-S25320832652008012100000)

Scan Tool Reference

1. «Scan Tool Output Controls»(ref-278010-S25097610112008012100000)
2. «Scan Tool Data List»(ref-278010-S06165027152008012100000)
3. «Scan Tool Data Definitions»(ref-278010-S35031572712008012100000)

Circuit/System Verification

Ignition ON, observe the scan tool Windshield Wiper Switch parameter while rotating the wiper switch. The reading should change between Off, Intermittent, and Low.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Turn Signal Multifunction Switch Replacement»(ref-278000-S21752461752008012100000)
2. «Control Module References»(ref-278020-S09054666032008012100000) for BCM replacement, setup, and programming

Symptoms - Wiper/Washer Systems

1. Perform «Diagnostic System Check - Vehicle»(ref-278018-S19353494792008012100000) , 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. Review the system description and operation in order to familiarize yourself with the system functions. Refer to «Wiper/Washer System Description and Operation»(ref-278010-S38606246202008012100000) .

Intermittent

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

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Wiper/Washer Connector End Views

Electrical Information Reference

1. «Circuit Testing»(ref-278019-S01379251932008012100000)
2. «Connector Repairs»(ref-278019-S06982211772008012100000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-278019-S21810776732008012100000)
4. «Wiring Repairs»(ref-278019-S25320832652008012100000)

Scan Tool Reference

1. «Scan Tool Output Controls»(ref-278010-S25097610112008012100000)
2. «Scan Tool Data List»(ref-278010-S06165027152008012100000)
3. «Scan Tool Data Definitions»(ref-278010-S35031572712008012100000)

BCM and Wiper Switch Verification

1. Ignition ON, observe the scan tool BCM Windshield Wiper Switch parameter. The reading should display Off, Intermittent, Low and High while rotating the wiper switch. If one or more of the wiper delay parameters are inoperative and the wiper low speed parameter functions, replace the turn signal/multifunction switch. If the low speed and/or high speed parameters are inoperative, perform the Multifunction Switch Circuit/System Testing and/or the Multifunction Switch Component Test.
2. Observe the scan tool BCM Wiper Park Switch parameter. The reading should display Active when the wipers are parked and Inactive with the wipers ON or out of the park position. If the Wiper Park Switch parameter is always Active or Inactive, perform the Wipers do not Park Circuit/System Testing.
3. If all wiper position parameters displayed correctly on the scan tool, perform the Wiper Motor Circuit/System Testing and/or the Wiper Motor Component Test

BCM and Wiper Motor Verification

1. Command the windshield wiper motor to the off, low speed and high speed modes with a scan tool. The wipers should perform the commanded state. If one or more of the commanded states do not work, perform the Wiper Motor tests in Circuit/System Testing and/or Component test.
2. If all the wiper motor speeds function, perform the Multifunction Switch Circuit/System Testing and/or the Multifunction Switch Component Test.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Turn Signal Multifunction Switch Replacement»(ref-278000-S21752461752008012100000)
2. «Windshield Wiper System Module Replacement»(ref-278010-S26088428302008012100000)
3. «Underhood Electrical Center or Junction Block Replacement»(ref-278007-S27290193332008012100000)
4. «Control Module References»(ref-278020-S09054666032008012100000) for BCM replacement, programming, and setup

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Displays and Gages Connector End Views

Electrical Information Reference

1. «Circuit Testing»(ref-278019-S01379251932008012100000)
2. «Connector Repairs»(ref-278019-S06982211772008012100000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-278019-S21810776732008012100000)
4. «Wiring Repairs»(ref-278019-S25320832652008012100000)

Scan Tool Reference

Scan Tool Data List

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Washer Solvent Container Level Sensor Replacement (Chevrolet)»(ref-278010-S37493832062008012100000) or «Washer Solvent Container Level Sensor Replacement (GMC)»(ref-278010-S38873480602008012100000)
2. «Control Module References»(ref-278020-S09054666032008012100000) for IPC replacement, programming, and setup

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Wiper/Washer Connector End Views

Electrical Information Reference

1. «Circuit Testing»(ref-278019-S01379251932008012100000)
2. «Connector Repairs»(ref-278019-S06982211772008012100000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-278019-S21810776732008012100000)
4. «Wiring Repairs»(ref-278019-S25320832652008012100000)

Scan Tool Reference

1. «Scan Tool Output Controls»(ref-278010-S25097610112008012100000)
2. «Scan Tool Data List»(ref-278010-S06165027152008012100000)
3. «Scan Tool Data Definitions»(ref-278010-S35031572712008012100000)

1. Ignition on, verify that a test lamp connected to ground does not illuminate on either side of the FRT WASH fuse while the windshield washer switch is inactive. If the test lamp illuminates on one or both sides of the fuse perform the Windshield Washer Pump Always On Circuit Test.
2. Ignition on, verify that a test lamp connected to ground illuminates on at least one side of the FRT WASH fuse while pressing the windshield washer switch. If the test lamp does not illuminate on either side of the fuse, perform the Windshield Washer Switch Circuit Test.
3. If the test lamp illuminates on one or both sides of the fuse perform the Windshield Washer Pump Circuit Test.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Turn Signal Multifunction Switch Replacement»(ref-278000-S21752461752008012100000)
2. «Washer Pump Replacement (Silverado)»(ref-278010-S19666778892008012100000)
3. «Underhood Electrical Center or Junction Block Replacement»(ref-278007-S27290193332008012100000)
4. «Control Module References»(ref-278020-S09054666032008012100000) for BCM replacement, programming, and setup.

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Wiper/Washer Connector End Views

Electrical Information Reference

1. «Circuit Testing»(ref-278019-S01379251932008012100000)
2. «Connector Repairs»(ref-278019-S06982211772008012100000)
3. «Testing for Intermittent Conditions and Poor Connections»(ref-278019-S21810776732008012100000)
4. «Wiring Repairs»(ref-278019-S25320832652008012100000)

Scan Tool Reference

1. «Scan Tool Output Controls»(ref-278010-S25097610112008012100000)
2. «Scan Tool Data List»(ref-278010-S06165027152008012100000)
3. «Scan Tool Data Definitions»(ref-278010-S35031572712008012100000)

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Accessory Switch Replacement (without RPO SLT) or Accessory Switch Replacement (with RPO SLT)

Moisture Sensing Feature Inoperative

Moisture Sensing Feature Inoperative

Wiper Blade Element Check

1. Remove the wiper blades from the wiper arms. Refer to «Windshield Wiper Blade Replacement»(ref-278010-S26959734722008012100000) .
2. Look down the length of the blade element.
3. Replace the wiper blade if the rubber element which contacts the glass is not on the centerline of the blade +/-15 degrees.
4. Install the wiper blades on the wiper arms. Refer to «Windshield Wiper Blade Replacement»(ref-278010-S26959734722008012100000) .

Scheme 25

Windshield Washer Hose Replacement

Windshield Glass Cleaning

Clean the windshield glass with windshield cleaner. The cleaner used should be one that will not harm the paint finish or scratch the glass. The windshield glass is clean when water no longer beads, but sheets across the entire glass surface.

Blade Element Cleaning

1. Lift the wiper blade assemblies off of the windshield glass.
2. Clean the wiper blade element with a clean cloth saturated with full strength washer solution.
3. Rinse the wiper blade assemblies with water.
4. Place the wiper blade assemblies back onto the windshield glass.

Wiper Chatter Repair

Some vehicles may exhibit a condition where the windshield wiper blades chatter or wipe unevenly. Several different conditions can cause the wiper blade chatter. To completely repair wiper blade chatter, all of the following should be checked and repaired as necessary

1. The windshield glass must be clean.
2. The wiper blade element must be clean.
3. The wiper arm tip pressure must be within specifications.
4. The wiper blade element set must be within specifications.

Windshield Wipers

The windshield wiper/washer switch signal circuits are inputs to the body control module (BCM) and the BCM controls wiper motor low speed operation, washer pump and high speed operation. The windshield wiper/washer switch is provided a low reference from the BCM and each of the switch signal circuits is supplied 12 volts through a resistor and monitored within the BCM. During LOW or INTERMITTENT operation the wiper switch low signal circuit is closed to the low reference circuit through a series of resistors within the switch assembly and the signal circuit voltage monitored by the BCM will depend on the switch contact location to the resistor assembly. During HIGH or WASH operation the high and wash switch signal circuits are closed directly to the low reference circuit within the switch assembly and nearly all the signal circuit voltage will be dropped across the BCM resistors. The BCM controls the wiper motor through the WIPER 1 relay and the WIPER 2 relay. During any wiper motor function that uses low speed the BCM supplies the voltage to energize the WIPER 1 relay and battery voltage will be supplied from the WIPER 1 relay through the de-energized WIPER 2 relay to the wiper motor low speed control circuit. During high speed wiper motor operation the WIPER 1 relay is energized as in low speed and the BCM provides a ground to energize the WIPER 2 relay and the battery voltage is supplied to the wiper motor high speed control circuit. Wiper motor park operation is controlled by the BCM using an input from the park switch within the wiper motor assembly. The BCM supplies the park switch signal circuit 12 volts through a resistor then monitors the circuit. Whenever the wiper motor is out of the park position the park switch signal circuit is closed to ground and nearly all the signal circuit voltage will be dropped across the BCM resistor. 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 and the BCM will park the wipers the next time the ignition is cycled ON.

Moisture Sensitive Wipers

The outside moisture sensor monitors moisture accumulation on the windshield and uses a windshield wiper/washer switch status input to provide wipe commands to the body control module (BCM). The DELAY positions on the wiper/washer switch are used to activate the AUTOMATIC rain sensing operating mode. They are also used to adjust the level of sensitivity to moisture accumulation, which determines the dwell time for commanding a wiper motor wipe cycle.

Accessory voltage is supplied to the outside moisture sensor from the BCM. The sensor is grounded through the ground circuit and G200. Whenever the ignition is in the run or accessory positions, the BCM sends the wiper/washer switch status using a pulse width modulation (PWM) signal through the outside moisture sensor signal 1 circuit to the outside moisture sensor. When a wipe cycle is needed, the moisture sensor sends a PWM voltage signal through the moisture sensor signal 2 circuit back to the BCM requesting the wiper operation.

The outside moisture sensor uses the moisture sensor signal 2 circuit to command wiper motor wipe cycles and to confirm the moisture sensor signal 1 is being received. If at anytime communication between the outside moisture sensor and BCM is lost, the BCM will use the inputs from the windshield wiper/washer switch in the delay positions to operate the wiper motor at continuous variable delay intervals.

Windshield Washers

When the windshield Wash switch is pressed, ground is applied through the switch contacts and the windshield washer switch signal circuit to the body control module (BCM) indicating the windshield wash request. The BCM then energizes the WPR relay, as stated above, and the WSH relay by applying ground through the control circuit to the coil side of the relay. With the wash relay energized, battery voltage from the WPR fuse is applied through the switch side of the relay and out to the control circuit of the windshield washer fluid pump. The wiper motor will operate for 2 wipe cycles after the wash switch is released.

Heated Windshield Washers

The windshield washer solvent heater operates with the standard windshield wiper washer system, and when a heated washer cycle is activated the solvent heater controls the windshield washers through the washer switch signal circuit to the body control module (BCM). The heater is supplied with high current power and ground circuits that are used to energize the heater coils. The low current logic voltage is supplied to the heater through the RUN relay in the underhood fuse block. The RUN relay is a PCB relay energized by the BCM only while the engine is running. The heated washer cycle operation is activated by a separate switch located on the instrument panel accessory switch assembly. When the heated washer fluid switch is pressed the heated washer switch signal circuit is momentarily grounded and the heated washer cycle is activated. During the heated wash cycle the 3 heater elements in the solvent heater are energized, and when the solvent temperature reaches approximately 70° C (160° F) the heater grounds the washer switch signal circuit until the heated solvent is dispensed. The heated washer cycle will run 4 heat and wash actions unless deacitvated by the heated washer switch signal.