System Operation
System Diagram
E363825 *.sttxt { visibility: hidden; } *.stcallout { visibility: visible; } 1 Wiper relay 2 BJB 3 Rain Sensor 4 Rear Wiper Motor 5 Windshield Wiper Motor 6 BJB 7 Rear Window Washer Relay 8 Washer Motor 9 Wiper/ Washer Switch 10 IPC 11 BCM 12 PCM 13 GWM 14 SCCMItem | Description |
---|---|
1 | Wiper Relay |
2 | BJB |
3 | Rain Sensor |
4 | Rear Wiper Motor |
5 | Windshield Wiper Motor |
6 | BJB |
7 | Rear Window Washer Relay |
8 | Washer Motor |
9 | Wiper/Washer Switch |
10 | IPC |
11 | BCM |
12 | PCM |
13 | GWM |
14 | SCCM |
Network Message Chart
SCCM Network Input Messages
Broadcast Message | Originating Module | Message Purpose |
---|---|---|
Vehicle speed | PCM | The SCCM uses vehicle speed information for operation of the speed sensitive wiper function. |
Message center feature configuration | IPC | The SCCM uses the message center feature configuration to enable/disable the courtesy wipe and the rain sensitive wiper features. |
Rain Sense ON/OFF | IPC | Used by the SCCM to toggle the rain sense function ON and OFF. |
Courtesy Wipe ON/OFF | IPC | Used by the SCCM to toggle the courtesy wipe function ON and OFF. |
Transmission in reverse | PCM | Used by the SCCM to operate the reverse gear wipe function. |
BCM Network Input Messages
Broadcast Message | Originating Module | Message Purpose |
---|---|---|
Front wiper status | SCCM | The BCM uses the wiper status information for operation of the wiper activated headlamps feature. |
Windshield Wipers
The wiper relay is energized when the ignition is on and provides voltage to the windshield wiper motor and the rain sensor.
The SCCM monitors the wiper/washer switch inputs and sends the wiper/washer switch data to the windshield wiper motor through a LIN circuit.
Based on the input, the windshield wiper motor activates the appropriate wash, low, high and intermittent or rain sense modes. The logic of the wiper operation is contained within the windshield wiper motor.
When the wiper/washer switch is in the high speed setting, the windshield wiper motor also receives a ground signal directly from the SCCM , bypassing the logic within the windshield wiper motor module. This fail-safe circuit makes sure the windshield wipers function in high speed mode in the event of a LIN communication failure.
Mist Wipe
When the mist wipe function is activated, the SCCM sends the request to the driver side windshield wiper motor over the LIN to perform a single wipe of the windshield. The windshield wipers operate for as long as the mist wipe function is active.
Windshield Washer
When the wiper/washer switch is activated, the SCCM sends the washer request to the windshield wiper motor over the LIN . The windshield wash relay is internal to the windshield wiper motor. When the windshield wiper motor activates the windshield wash relay, voltage is provided to the washer pump, directing washer fluid to the windshield. If equipped with a front camera, washer solvent is also directed to the front camera lens when the washer pump is active. When the switch is released, the windshield wiper motors will continue to activate for 3 additional wipes and then turn off.
Ground for the washer pump is provided through the rear window washer relay, integral to the BJB .
Courtesy Wipe
If the wiper/washer switch is off when the when the windshield washer is requested, a few seconds after the windshield wash cycle has completed, an additional wipe of the windshield occurs to clear any remaining fluid that remains on the windshield.
Intermittent Wipers
When the wiper/washer switch is in an intermittent setting, the windshield wiper motors activate at timed intervals. The lower the setting, the longer the interval between wipes.
Speed Dependent Wipers
When the wiper/washer switch is in any intermittent setting except the lowest setting, the speed dependent feature increases the frequency of wiping as the vehicle speed increases to compensate for the extra moisture that accumulates on the windshield.
The SCCM receives the vehicle speed from the PCM . The SCCM then sends the vehicle speed data to the driver side windshield wiper motor through the LIN .
Rain Sensitive Wipers (if equipped)
When equipped, the rain sensitive wiper feature replaces the intermittent wiper feature. The rain sensitive feature is active when the wiper/washer switch is in any of the 7 auto/intermittent sensitivity settings. The setting closest to OFF is the least sensitive to moisture, the highest setting being the most sensitive to moisture.
The rain sensor sends data through the LIN to the windshield wiper motor. Based on the data received from the rain sensor and the auto/intermittent setting from the wiper/washer switch, the system automatically activates and adjusts the wiper speed and frequency when moisture is detected on the windshield.
If a fault is detected with the rain sensitive feature, the windshield wipers change to a default intermittent mode. The timing of the wipers correspond to a standard intermittent setting based on the auto/intermittent sensitivity setting on the wiper/washer switch.
Wiper Activated Exterior Lamps
The BCM turns the exterior lamps on within 10 seconds of the windshield wipers being activated by the wiper/washer switch when the headlamp switch is in the AUTO position. Approximately 30 seconds after the windshield wipers turn off, the BCM turns the exterior lamps off.
If equipped with rain sensitive wipers, the BCM turns the exterior lamps on when the rain sensitive wipers are activated by moisture detected on the windshield when the headlamp switch is in the AUTO position. Shortly after the rain sensitive wipers are deactivated (moisture no longer detected on the windshield), the BCM turns the exterior lamps off.
Rear Window Wiper
When the wiper/washer switch is in the INT 1 or INT 2 (continuous wipe) position, the SCCM sends the request to the windshield wiper motor through the LIN. When the request is received, the windshield wiper motor momentarily supplies ground to the rear window wiper motor, activating the motor. The position of the wiper/washer switch determines how many times per minute the windshield wiper motor provides ground to activate the rear window wiper motor.
The rear window wiper motor is self-parking.
Rear Window Washer
When the rear window washer switch is activated, the SCCM sends the request to the windshield wiper motor through the LIN . The windshield wiper motor energizes the rear washer relay (integral to the BJB ) and activates the rear window wiper motor. When the windshield wiper motor activates the rear window wash relay, voltage is provided to the washer pump, directing washer fluid to the rear window. If equipped with a rear camera, washer solvent is also directed to the rear camera lens when the washer pump is active. When the switch is released, the rear window wiper motor continues to operate for 3 additional wipes and then turns off.
Ground for the washer pump is provided through the windshield washer relay within the windshield wiper motor.
Component Description
Wiper/Washer Switch
The wiper/washer switch is mounted directly to the SCCM . The windshield wiper/washer inputs to the SCCM are:
The rear wiper/washer inputs to the SCCM are:
Windshield Wiper Motor
The windshield wiper motor is a smart motor that receives mode requests from the SCCM through a LIN . The windshield wiper motor continuously monitors the wiper/washer switch inputs from the SCCM and (if equipped) the rain sensor when the ignition is on. Based on the wiper/washer switch inputs from the SCCM, the windshield wiper motors activates to achieve the requested mode.
The windshield wiper motor is mounted to the wiper and linkage assembly.
Washer Pump
The washer pump is controlled by the windshield wiper motor. The front and rear washer system share the same washer reservoir and a bi-directional washer pump. The washer pump delivers washer fluid to the windshield when the windshield wiper motor activates the windshield washer relay (internal to the windshield wiper motor), which provides voltage to the washer pump. Ground for the washer pump is provided through the rear washer relay (integral to the BJB ). When activated, the washer pump delivers washer fluid to the windshield.
When the windshield wiper motor energizes the rear washer relay, the rear washer relay provides voltage to the washer pump. Ground for the washer pump is provided through the windshield washer relay (internal to the windshield wiper motor). When activated, the pump delivers washer fluid to the rear window.
Rain Sensor
The rain sensor uses an infrared beam to optically sense water on the windshield. The intensity of the reflected beam is measured and compared to the intensity of the transmitted beam. If there is water on the surface of the windshield, the beam distorts, reducing the intensity of the beam. If the beam is not reflected completely, it is interpreted as rain on the windshield and the windshield wipers are activated.
A gel-type lens is used as the interface between the rain sensor and the windshield. The rain sensor gel-type lens is part of the rain sensor. If the lens is missing or damaged, the rain sensing wipers can be inoperative, and a new sensor must be installed.
Rear Wiper Motor
The rear window wiper motor contains an integrated relay and a single speed motor. When the windshield wiper motor momentarily energizes the integrated relay within the rear wiper motor, the rear window wiper activates. The integrated relay is used to continue the rear window wipe and park the wiper motor.
Special Tool(s) / General Equipment
205-123 (T78P-1177-A)