For 1990-2009 cars

### Wiper/Washer System Components

The windshield Wiper/Washer system consists of the following components:

• | Body Control Module (BCM).

• | Washer pump.

• | Washer pump relay.

• | Washer solvent container.

• | Wiper arm and blade assemblies.

• | Wiper motor.

• | Wiper/washer switch.

• | F15 30 A fuse.

• | F21 15 A fuse.

• | Wiper relay.

• | Wiper high relay.

• | Moisture Sensor (If Equipped).

• | Heated Washer System (If Equipped).

### Windshield Wiper/Washer System Power and Ground

With the ignition in the ON position, accessory voltage is supplied through a 30A fuse to the wiper relay and the wiper high relay. Accessory voltage is supplied through a 15A fuse to the washer pump relay when the ignition is in the ON position. All of the above mentioned fuses and relays are located in the underhood fuse block.

### Modes Of Operation

• | Manual low.

• | Mist.

• | Intermittent.

• | Manual high.

• | Wash.

### Low Speed Operation

When the wiper switch is in the low speed position, ground is applied through a resistor internal to the switch and the wiper switch low signal circuit to the BCM. In response to this signal, the BCM energizes the wiper relay. Since the wiper high relay is de-energized and its switch contacts are normally closed to the low speed control circuit of the windshield wiper motor, the motor will operate at low speed.

### Mist Operation

Windshield wiper/washer system mist operation is identical to wiper low speed operation, except that the mist switch is a press and release type switch. When the wiper switch is moved to the mist position and released, low speed wiper motor operation is started and will continue until 1 wipe cycle is complete. If the wiper switch is moved to the mist position and held, the wiper motor will operate in the low mode until the switch is released.

### Intermittent Operation

Windshield wiper intermittent operation is a low speed wiper motor function with a variable delay interval between the wiper motor cycles. The delay interval is determined by a series of 6 resistors within the wiper/washer switch. The BCM monitors the wiper switch low signal circuit to determine the delay interval between the low speed wiper motor wipe cycles.

### High Speed Operation

When the wiper switch is in the high speed position, ground is applied through the windshield wiper switch high signal circuit to the BCM indicating the wiper high speed request. In response to this signal, the BCM then energizes the wiper relay, by applying battery voltage through the wiper relay control circuit to the coil side of the relay. This allows battery positive voltage from the F21 15A fuse to flow through the switch input side of the wiper relay and out to the switch input side of the wiper high relay. At the same time, the BCM also energizes the wiper high relay by applying ground through the control circuit to the coil side of the wiper high relay. As the wiper high relay is energized and its switch contacts closed to the high speed control circuit of the wiper motor, the motor will operate at high speed.

### Wash Operation

In the wash position windshield wiper/washer switch grounds the control circuit of the windshield washer pump to the BCM. The BCM monitors this voltage input to detect when a wash cycle is requested so it can enable the wipers. The BCM energizes the wiper relay which will operate the windshield wiper motor at low speed.

The windshield washer pump sprays solvent onto the windshield. The windshield wipers operate at low speed for 3-5 wipes and returns to the park position.

### Moisture Sensitive Wipers (If Equipped)

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 through the 10A Fuse, located in the I/P fuse block. The sensor is grounded through the ground circuit .. 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.

### Heated Washer System (If Equipped)

The Heated Washer System consists of the following components:

• | Windshield washer fluid heater assembly

• | Heated washer fluid switch

• | Htd_Wsh_Htr Fuse 60 A

• | Htd_Wsh_Ign Fuse 10 A

The heated washer fluid module is located near the brake master cylinder. High current battery voltage is supplied to the windshield washer fluid heater assembly from a 60A inline fuse. The washer fluid heater uses this voltage to power the 3 heater coils. Battery positive voltage from the 10A F38 Fuse located in the underhood fuse block is applied to the windshield washer fluid heater assembly with the ignition in the ON position. This voltage is used to power up the logic in the heater assembly. Approximately 5 seconds after the ignition is turned on the washer fluid heater assembly will enter standby mode. During standby mode the heater assembly turns on 1 of the 3 heater elements to maintain a fluid temperature of 56°C (132°F). When the heated wash switch is pressed, the module detects switch closure and starts heated wash sequence The Instrument Cluster (IPC) will display the HEATED WASHER FLUID INDICATOR while the heater assembly heats the wash fluid to approximately 70°C (160°F). The total duration of the initial heat up cycle may take up to 40 seconds. Once the proper temperature is reached, the heater assembly will request the body control module (BCM) to activate the windshield wash cycle. The heater assembly will maintain an active wash request until the wash fluid temperature drops to 40° C when the wash cycle request will be de-activated allowing the wash fluid to heat up again. The fluid heating and wash application will automatically be repeated 3 more times. Upon completion of the 4 wash cycles, the system will transition to off. The automatic heated wash mode may be terminated at any time by pressing the heated washer fluid switch.