Wiper System & Washer System: Overview Chevrolet TrailBlazer I

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 2. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.
2. 5. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Scheme 26

Scheme 27

The numbers below refer to the step numbers on the diagnostic table.

1. 2. This step verifies that the fault is current.
2. 3. This step verifies the switch input to the BCM.
3. 4. This step determines if the fault is in the headlamp washer switch. If the switch input to the BCM changes to an inactive state when disconnected the switch contacts are stuck or shorted to ground.

Scheme 28

The numbers below refer to the step numbers on the diagnostic table.

1. 3. Tests for battery positive voltage to the high side of the relay coil. The WASH fuse supplies power to the headlamp washer and rear washer relays.
2. 4. Tests the ability of the BCM to energize the relay.
3. 5. Tests for a condition which causes the relay to remain energized at all times.

Scheme 29

Scheme 30

Symptoms - Wiper/Washer Systems

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

1. Perform the «DIAGNOSTIC SYSTEM CHECK - WIPER/WASHER»(ref-188870-S37776613352005090500000) before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Wiper/Washer System «DESCRIPTION AND OPERATION»(ref-188870-S39845927152005090500000) «REAR WIPER/WASHER SYSTEM DESCRIPTION AND OPERATION»(ref-188870-S15906424742005090500000) «HEADLAMP WASHER SYSTEM DESCRIPTION AND OPERATION»(ref-188870-S37436919752005090500000)

The numbers below refer to the step numbers on the diagnostic table.

1. 5. This step tests for continuity through the 390 Q. resistor in the windshield wiper/washer switch.
2. 6. This step tests for continuity through the delay resistors in the windshield wiper/washer switch. The measured resistance will change in sequence from low to high as the delay speed is increased.

Scheme 31

Scheme 32

Scheme 33

Scheme 34

Scheme 35

Scheme 36

Scheme 37

The numbers below refer to the step numbers on the diagnostic table.

1. 3. If any of the liftgate or liftglass switch fails ajar the rear wiper will not operate.
2. 4. This step determines if the liftgate control module is receiving the correct switch position message from the body control module.
3. 5. This step determines if the liftgate control module is attempting to operate rear wiper motor in the requested operating mode.
4. 6. This step tests the resistance through the rear wiper switch. The measured resistance will be highest in the OFF position and reduce as the switch is turned from positions 1 through 3.

Scheme 38

Scheme 39

Scheme 40

1. Run the wiper arms to the mid-wipe position.
2. Remove the wiper blades from the wiper arms. Refer to «WIPER ARM BLADE REPLACEMENT»(ref-188870-S30957811792005090500000) .
3. Attach a scale to the end of the wiper arm and measure the force required to lift the wiper arm perpendicular to the windshield to the normal working height (the height with the blade attached).
4. Replace the wiper arms if the measurement is not within the specified values. Refer to «WIPER ARM BLADE REPLACEMENT»(ref-188870-S30957811792005090500000) . Tip Pressure 7.8-9.5 (28-34 oz.)

Scheme 41

1. Remove the wiper blades from the wiper arms. Refer to «WIPER ARM BLADE REPLACEMENT»(ref-188870-S30957811792005090500000) .
2. Look down the length of the blade element.
3. Replace the wiper blade element if the rubber element which contacts the glass is not on the centerline of the blade +/-15 degrees. Refer to «WIPER BLADE ELEMENT REPLACEMENT»(ref-188870-S12364138772005090500000) .
4. Install the wiper blades on the wiper arms. Refer to «WIPER ARM BLADE REPLACEMENT»(ref-188870-S30957811792005090500000) .

Scheme 42

1. Remove the air cleaner element. Refer to Air Cleaner Element Replacement in Engine Controls-4.2L.
2. Remove the air cleaner/washer container assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls-4.2L.
3. Remove the washer pumps from the container assembly. Refer to «WASHER PUMP REPLACEMENT (HEADLAMPS)»(ref-188870-S03955109172005090500000) or «WASHER PUMP REPLACEMENT (WINDSHIELD)»(ref-188870-S28589182672005090500000) and «WASHER PUMP REPLACEMENT - REAR»(ref-188870-S09181761312005090500000) .

Scheme 43

1. Install the washer pumps to the container assembly. Refer to «WASHER PUMP REPLACEMENT (HEADLAMPS)»(ref-188870-S03955109172005090500000) or «WASHER PUMP REPLACEMENT (WINDSHIELD)»(ref-188870-S28589182672005090500000) and «WASHER PUMP REPLACEMENT - REAR»(ref-188870-S09181761312005090500000) .
2. Install the air cleaner/washer container assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls-4.2L.
3. Install the air cleaner element. Refer to Air Cleaner Element Replacement in Engine Controls-4.2L.

Scheme 44

1. Remove the washer solvent container. Refer to «WASHER SOLVENT CONTAINER REPLACEMENT»(ref-188870-S21358678172005090500000) .
2. Disconnect the headlamp washer hose from the pump (1).
3. Remove the pump (1) from the solvent container by carefully pulling pump from the retainer (3).
4. Remove the pump (1) from the sealing grommet (2).

Scheme 45

1. Install the pump (1) to the sealing grommet (2).
2. Install the pump (1) to the retainer (3) on the solvent container.
3. Connect the headlamp washer hose to the pump (1).
4. Install the washer solvent container. Refer to «WASHER SOLVENT CONTAINER REPLACEMENT»(ref-188870-S21358678172005090500000) .

Scheme 46

1. Remove the washer solvent container. Refer to «WASHER SOLVENT CONTAINER REPLACEMENT»(ref-188870-S21358678172005090500000) .
2. Disconnect the washer hose (4) from the pump (2).
3. Remove the pump (2) from the solvent container by carefully pulling pump from the retainer (1).
4. Remove the pump (2) from the sealing grommet (3).

Scheme 47

1. Install the pump (2) to the sealing grommet (3).
2. Install the pump (2) to the retainer (1) on the solvent container.
3. Connect the washer hose (4) to the pump (2).
4. Install the washer solvent container. Refer to «WASHER SOLVENT CONTAINER REPLACEMENT»(ref-188870-S21358678172005090500000) .

Scheme 48

Scheme 49

1. Remove the wiper arms. Refer to «WIPER ARM REPLACEMENT»(ref-188870-S34083005532005090500000) .
2. Remove the air inlet grille panel. Refer to AIR INLET GRILLE PANEL REPLACEMENT in Body Front End.
3. Remove the washer hose connection (1) from the nozzle.
4. Remove the washer nozzles from the air inlet grille panel by squeezing the retaining tabs (1).

Scheme 50

Scheme 51

1. Install the washer nozzles to the air inlet grille panel, by indexing the tab in the air inlet grille panel to the washer nozzle.
2. Be sure the retaining tabs (1) are secure.
3. Install the washer hose connection (1) to the washer nozzle.
4. Install the air inlet grille panel. Refer to AIR INLET GRILLE PANEL REPLACEMENT in Body Front End.
5. Install the wiper arms. Refer to «WIPER ARM REPLACEMENT»(ref-188870-S34083005532005090500000) .

Scheme 52

1. Remove the grille. Refer to GRILLE REPLACEMENT (GMC) or GRILLE REPLACEMENT (OLDSMOBILE) or GRILLE REPLACEMENT (CHEVROLET) in Exterior Trim.
2. Remove the headlamp washer hose quick connect from the nozzle located on the bottom of the fluid reservoir.
3. Remove the hose assembly from the vehicle.

Scheme 53

1. Install the hose assembly to the vehicle.
2. Install the headlamp washer hose quick connect to the nozzle.
3. Install the grille. Refer to GRILLE REPLACEMENT (GMC) or GRILLE REPLACEMENT (OLDSMOBILE) or GRILLE REPLACEMENT (CHEVROLET) in Exterior Trim.

Scheme 54

1. Remove the wiper arms. Refer to «WIPER ARM REPLACEMENT»(ref-188870-S34083005532005090500000) .
2. Remove the air inlet grille panel. Refer to AIR INLET GRILLE PANEL REPLACEMENT in Body Front End.
3. Disconnect the washer hose connections (1) from the washer nozzles.
4. Disconnect the washer hose from the clips (2) on the air inlet grille panel.
5. Remove the washer hose from the air inlet grille panel.

Scheme 55

1. Install the washer hose to the air inlet grille panel.
2. Connect the washer hose connections (1) to the washer nozzles.
3. Connect the washer hose to the clips (2) on the air inlet grille panel.
4. Install the air inlet grille panel. Refer to AIR INLET GRILLE PANEL REPLACEMENT in Body Front End.
5. Install the wiper arms. Refer to «WIPER ARM REPLACEMENT»(ref-188870-S34083005532005090500000) .

Scheme 56

1. Remove the grille. Refer to GRILLE REPLACEMENT (GMC) or GRILLE REPLACEMENT (OLDSMOBILE) or GRILLE REPLACEMENT (CHEVROLET) in Exterior Trim.
2. Remove the headlamp washer hose quick connect from the nozzle located on the bottom of the fluid reservoir.
3. Remove the hose assembly from the vehicle.

Scheme 57

1. Install the hose assembly to the vehicle.
2. Install the headlamp washer hose quick connect to the nozzle.
3. Install the grille. Refer to GRILLE REPLACEMENT (GMC) or GRILLE REPLACEMENT (OLDSMOBILE) or GRILLE REPLACEMENT (CHEVROLET) in Exterior Trim.

Scheme 58

1. Remove the wiper arms. Refer to «WIPER ARM REPLACEMENT»(ref-188870-S34083005532005090500000) .
2. Remove the air inlet grille panel. Refer to AIR INLET GRILLE PANEL REPLACEMENT in Body Front End.
3. Disconnect the washer hose connections (1) from the washer nozzles.
4. Disconnect the washer hose from the clips (2) on the air inlet grille panel.
5. Remove the washer hose from the air inlet grille panel.

Scheme 59

1. Install the washer hose to the air inlet grille panel.
2. Connect the washer hose connections (1) to the washer nozzles.
3. Connect the washer hose to the clips (2) on the air inlet grille panel.
4. Install the air inlet grille panel. Refer to AIR INLET GRILLE PANEL REPLACEMENT in Body Front End.
5. Install the wiper arms. Refer to «WIPER ARM REPLACEMENT»(ref-188870-S34083005532005090500000) .

Scheme 60

1. Mark the position of the wiper blade on the windshield with a suitable marker or a piece of masking tape.
2. Remove the cover from the nut on the wiper arm.
3. Remove the nut from the wiper arm. IMPORTANT: Use a battery terminal puller to remove the wiper arm if rocking the wiper arm fails to loosen it from the drive shaft.
4. Rock the wiper arm back and forth to loosen it from the drive shaft.
5. Remove the wiper arm from the drive shaft.
6. Remove the wiper arm blade from the wiper arm. Refer to «WIPER ARM REPLACEMENT»(ref-188870-S34083005532005090500000) .
7. Clean the knurls of the drive shaft with a wire brush.

Scheme 61

1. Install the wiper arm blade to the wiper arm. Refer to «WIPER ARM REPLACEMENT»(ref-188870-S34083005532005090500000) .
2. Position the wiper arm so that the wiper blade aligns with the mark made on the windshield before removal.
3. Install the wiper arm onto the drive shaft. NOTE: Refer to Fastener Notice in Cautions and Notices.
4. Install the nut on the drive shaft. Tighten Tighten the nut to 30 N.m (22 lb ft).
5. Install the cover on the nut.
6. Clean the locating mark or masking tape from the windshield.
7. Operate the wipers and inspect for proper operation.

Windshield Wiper/Washer System Operation

Accessory voltage and ground is supplied to the windshield wiper motor and provides the power for operating the wiper motor and logic power to the wiper motor module. The WASH, MIST, LOW, and DELAY modes are controlled by the windshield wiper/washer switch through a series of internal resistors. The windshield wiper switch supply voltage circuit is a 12-volt reference from the wiper motor module to the wiper/washer switch, and the switch position determines the point on the resistor assembly where the reference voltage is applied. The windshield wiper switch signal 1 circuit supplies the voltage from the resistor assembly to the wiper motor module and the signal voltage determines the operating mode. High speed operation is controlled by the windshield wiper/washer switch through the windshield wiper switch high signal circuit. The windshield wiper switch high signal circuit is supplied 12 volts by the wiper motor module and when the wiper/washer switch is turned to the HIGH position the windshield wiper switch high signal circuit is grounded through the switch ground circuit. The windshield washer pump is controlled through the windshield wash relay. The windshield wash relay coil and switch is supplied battery positive voltage, and during WASH mode the wiper motor module grounds the washer relay control circuit energizing the relay. When the relay is energized battery positive voltage to the switch side of the relay is supplied to the washer pump control circuit. The windshield wiper switch signal 2 circuit from the wiper motor module is used by the body control module as a signal to turn on the low beam headlamps.

Rear Wiper/Washer System Operation

The rear window wiper/washer switch is an input to the body control module. The requested rear wiper mode is sent to the liftgate control module by the body control module as a message on the serial data circuit, and the rear window wiper motor is controlled by the liftgate control module. The switch power circuit to the rear wiper/washer switch is a 12-volt reference supplied by the body control module. The rear wiper/washer switch is a series of resistors and the switch position is determined by the voltage of the rear wiper/washer switch signal circuit to the body control module. The rear wiper/washer switch has continuity at all times and the body control module expects a rear wiper/washer switch signal voltage in all switch positions including OFF. The rear wiper motor is supplied battery positive voltage and ground. The liftgate control module controls rear wiper motor operation through the rear wiper motor control circuit. The rear wiper motor control circuit is supplied a battery positive reference voltage by the rear wiper motor module and is pulse width modulated to ground by the liftgate control module. The duty cycle of the pulse width modulation determines the rear wiper motor operating mode. The lift glass and lift gate ajar switches are inputs to the liftgate control module and rear wiper motor operation will be disabled whenever an ajar condition exists. The rear window washer pump is controlled by the body control module through the rear washer relay. Battery positive voltage is supplied to the coil and switch sides of the rear washer relay. When the rear window wash request is active the body control module energizes the relay by grounding the relay coil through the rear washer relay control circuit. When the relay is energized battery positive voltage to the relay switch is supplied to the washer pump control circuit.

Headlamp Washer System Operation

The body control module controls the headlamp washer pump using a programmed pulse type wash sequence. The pulse washing sequence is a wash cycle for a programmed amount of time followed by a programmed amount of delay time to let the water soak which is then followed by another wash cycle for a programmed amount of time. The headlamp washer pump is controlled by the body control module through the headlamp washer relay. The headlamp washer switch signal circuit is supplied a 12-volt reference through a resistor then monitored within the body control module. The headlamp washer switch is open when in an inactive state. When the headlamp washer switch is activated the signal circuit is closed to ground. When the headlamp washer switch signal circuit is closed to ground the reference voltage is dropped across the resistor within the body control module. The low voltage on the headlamp washer switch signal circuit indicates to the body control module the switch status is active. Battery positive voltage is supplied to the coil and switch sides of the headlamp washer relay. When a headlamp wash request is active the body control module energizes the headlamp washer relay by grounding the relay coil through the headlamp washer relay control circuit. When the relay is energized battery positive voltage to the relay switch is supplied to the washer pump control circuit.