Principles of Operation

PRINCIPLES OF OPERATION

The windshield wiper motor is a smart wiper motor and has an integrated module. The internal components of the wiper motor module are the high/low relay, washer pump relay, and the run/park sensor.

The windshield wiper motor receives its inputs from the multifunction switch. These signals are ground reference signals. When the multifunction switch is placed in different positions, various input signals are selected and sent through circuits to the wiper motor. The wiper motor module identifies these selected input signals and activates the wiper motor to the selected function.

High Speed Windshield Wipers
High speed is activated when the multifunction switch supplies a ground to the windshield wiper motor module inputs and the internal hi/lo speed relay. The module then supplies ground for the run/park relay, which activates the relay, sending voltage to the high speed side of the wiper motor activating the high-speed mode. At the end of each cycle, the park sense determines the state of internal run/park relays for voltage or ground. Depending on the state of the relays whether or not the wiper motor module needs to request another cycle.

Low Speed Windshield Wipers
Low speed is activated when the multifunction switch supplies a ground to the windshield wiper motor module inputs and the internal hi/lo speed relay remains in the same state. The module then supplies ground for the run/park relay, which activates the relay, sending voltage to the low speed side of the wiper motor activating the low speed mode. At the end of each cycle, the park sense determines the state of internal run/park relays for voltage or ground. Depending on the state of the relays, the wiper motor module might request another cycle.

Intermittent Wiper Speed Windshield Wipers
The intermittent wiper speeds are activated with grounds. They are controlled by the multifunction switch inputs to the windshield wiper motor module. The module then activates the windshield wiper run/park relay coil and switches voltage through the windshield wiper high/low relay. The relay remains deactivated, supplying the voltage to the wiper motor low speed input and activates the windshield wiper motor. When the module receives the grounded input, the motor continues to operate until the Hall-effect sensor senses the motor magnet. The run/park sensor turns off, and the output to the run/park software deactivates the relay and disconnects the voltage to the motor. The wipers remain parked until the module completes a time-out and then repeats the intermittent wiper cycle.

Default Mode
The windshield wiper motor defaults to this mode when the run/park sensor does not sense the Hall-effect magnet inside the wiper motor. This can be caused by obstruction of the windshield wipers or binding linkage. The windshield wiper motor continues to operate in a high/low speed condition for a period of 60 seconds.

Washer System
The windshield washer is activated by the windshield wiper motor module when it receives a ground signal from the multifunction switch washer input. Depending on the correct ground, the internal wiper motor module activates the windshield washer relay (internal) by grounding the respective relay coil. When the relay is activated, it connects voltage to the washer pump.

Low Washer Fluid Level Lamp/Indicator
The low washer fluid lamp/indicator feature is controlled by the front electronic module (FEM) and the instrument cluster. The low washer fluid switch is hardwired to the FEM. If the fluid level is low, the FEM sends a message via the standard corporate protocol (SCP) communication network to the instrument cluster. The instrument cluster then processes the message and outputs an audible and visual warning.