System Operation

Wipers and Washers - Front

System Operation

System Diagram





Network Message Chart

Module Network Input Messages







Windshield Wiper Operation

The wiper relay is activated whenever the ignition is in the ON position. The wiper relay provides voltage to the windshield wiper motor.

The wiper system is activated by the wiper/washer switch. The SCCM (Steering Column Control Module) commands the windshield wiper motor to activate the appropriate wash, low, high and intermittent modes through a private LIN (Local Interconnect Network).

When the wiper/washer switch is in the HIGH position, the windshield wiper motor also receives a ground signal which is hardwired directly from the SCCM (Steering Column Control Module) (bypassing the logic within the module). This fail-safe circuit makes sure that the windshield wipers will function in HIGH speed mode in the event of a LIN (Local Interconnect Network) communication failure.

Wiper Activated Headlamps

If equipped with automatic headlamps, the BCM (Body Control Module) illuminates the exterior lamps within 10 seconds of the windshield wipers being activated by the wiper/washer switch when the headlamp control switch is in the AUTOLAMP position. The BCM (Body Control Module) continues to illuminate the exterior lamps for approximately 30 seconds after the windshield wipers have been turned off.

If equipped with rain sensitive wipers (feature must be enabled through the message center) and the wiper/washer switch is in one of the 5 auto/intermittent settings, the BCM (Body Control Module) illuminates the exterior lamps within 30 seconds of the windshield wipers being activated by moisture detected on the windshield when the headlamp control switch is in the AUTOLAMP position. The BCM (Body Control Module) continues to illuminate the exterior lamps for approximately 60 seconds after the windshield wipers have been deactivated (moisture no longer detected on the windshield).

Speed Dependent Wipers

The speed dependent feature increases the frequency of wiping to compensate for the extra moisture that accumulates on the windshield as the vehicle speed increases. This feature activates when the wiper/washer switch is in any intermittent setting except the INT 1 position. As vehicle speed increases, the speed dependent feature gradually shortens the delay between wipes.

Rain Sensitive Wipers

When equipped, the rain sensitive wiper feature replaces the intermittent wiper feature. There are no interval (intermittent) wipe functions available when the rain sensitive feature is active. The wiper system only wipes when the rain sensing feature detects moisture on the windshield. The rain sensitive feature is active when the wiper/washer switch is in any of the 5 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 (Local Interconnect Network) to the windshield wiper motor. When the rain sensitive wiper feature is enabled, based on the data received from the rain sensor and the auto/ intermittent setting on the wiper/washer switch, the system automatically activates and adjusts the wiper speed and frequency when moisture is detected on the windshield.

The rain sensitive wiper feature can be enabled/disabled through the message center.

When the rain sensitive wipers are disabled from the message center, or the windshield wiper motor detects a fault with the rain sensor input, the windshield wiper motor changes 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.

Washer System

When the washer switch on the end of the wiper/washer stalk is pressed, the SCCM (Steering Column Control Module) sends the request to the windshield wiper motor through the LIN (Local Interconnect Network). The windshield wiper motor activates the wash relay (which is internal to the windshield wiper motor) providing voltage to the washer pump and directing washer fluid to the windshield.

Courtesy Wipe

When the windshield washer system is activated, the wipers cycle 3 times with washer fluid, followed by one final wipe a few seconds later to clear any remaining fluid that is dripping from the top of the windshield. This feature can be enabled/disabled through the message center. For additional information on enabling/disabling this feature, refer to the Owner's Literature.