Ford Fusion: Wipers and Washers / Wipers and Washers - System Operation and Component Description. Description and Operation

System Operation

System Diagram

Network Message Chart

  SCCM Network Input Messages

  BCM Network Input Messages

Windshield Wipers

The wiper relay, integrated into the BJB is energized when the ignition is on providing voltage to the windshield wiper motors and the rain sensor (if equipped).

The SCCM monitors the wiper/washer switch inputs and sends the wiper/washer switch data to the driver side windshield wiper motor through a LIN. The driver side windshield wiper motor then coordinates the wiper operation with the passenger side windshield wiper motor (using an isolated communication circuit between them) to prevent interference between the windshield wipers while they are operating. The driver side windshield wiper motor is the primary wiper motor and controls the operation of both windshield wipers.

Based on the input, the driver side 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 driver side windshield wiper motor.

When the wiper/washer switch is in the high speed setting, the driver side windshield wiper motor also receives a ground signal directly from the SCCM (bypassing the logic within the 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 driver side windshield wiper motor over the LIN. The windshield wash relay is internal to the driver side windshield wiper motor. When the driver side windshield wiper motor activates the windshield wash relay, voltage is provided to the washer pump, directing washer fluid to the windshield. When the switch is released, the windshield wiper motors continue to activate for 3 additional wipes and then turn off.

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 6 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 driver side 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.

Component Description

Wiper/Washer Switch

The wiper/washer switch is mounted directly to the SCCM. The windshield wiper/washer inputs to the SCCM are:

• Mist wipe
• Windshield wash
• Off
• AUTO 1/INT 1
• AUTO 2/INT 2
• AUTO 3/INT 3
• AUTO 4/INT 4
• AUTO 5/INT 5
• AUTO 6/INT 6
• Low
• High

Windshield Wiper Motor

The windshield wiper motors contain a logic module, internal sensors to monitor the wiper arm position and a multi-speed motor. The logic module from the driver side windshield wiper motor continuously monitors the wiper/washer switch inputs from the SCCM and (if equipped) the rain sensor when the ignition is on. Depending on the input, the wiper motors activate to achieve the desired request.

The driver side windshield wiper motor is the primary wiper motor and controls the operation of both windshield wipers.

The wiper arms are mounted directly to the wiper motors.

Washer Pump

The washer pump is controlled by the driver side windshield wiper motor. The washer pump delivers washer fluid to the windshield when the driver side windshield wiper motor activates the windshield washer relay (internal to the driver side windshield wiper motor), which provides voltage to the washer pump. When activated, the washer pump delivers washer fluid to the windshield.

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. If the lens is missing or damaged, the rain sensing wipers can be inoperative. The rain sensor gel-type lens can be replaced separately on a rain sensor of this type.