Principles of Operation

PRINCIPLES OF OPERATION

The wiper system has 5 different operating modes: OFF mode, LOW SPEED mode, HIGH SPEED mode, INTERVAL mode, and SOFTWARE SAFE mode.

HIGH SPEED is activated when the multifunction switch supplies ground to the windshield wiper motor module inputs. The windshield wiper motor module then supplies ground to the run/park sense and high/low relay coil, activating the relay with voltage supplied from the battery through the central junction box (CJB). When the windshield wiper motor module receives voltage from the run/park sensor, it removes ground from the run/park sensor, deactivating it. The windshield wiper motor continues to operate from voltage connected through the run/park sensor until the Hall-effect sensor senses magnetism in the motor. When the Hall-effect sensor senses magnetism in the motor, the windshield wiper motor returns to the PARK position, the internal run/park sensor grounds the windshield wiper motor module input and the windshield wiper motor module removes ground from the windshield wiper high/low relay coil, deactivating the high/low relay and windshield wiper motor. The windshield wiper motor module continues to cycle the windshield wipers until the inputs from the multifunction switch are changed from the HIGH SPEED position.

LOW SPEED is activated when the multifunction switch supplies a specific ground to the speed inputs of the windshield wiper motor module. The windshield wiper motor module then supplies ground to only the windshield wiper run/park relay coil, activating it. When the windshield wiper run/park relay is activated, the deactivated windshield high/low relay connects voltage to the windshield wiper motor low input, activating the wiper motor. The windshield wiper motor module continues to operate the windshield wiper motor in the same manner as in high speed, but in LOW SPEED with the wiper motor connected to the low speed input.

The INTERVAL wiper speed is activated with grounds controlled by the multifunction switch inputs to the windshield wiper motor module. The windshield wiper motor module then activates the windshield wiper run/park relay coil and switches voltage through the windshield wiper high/low relay. The high/low relay remains deactivated supplying the voltage to the wiper motor low speed input and activates the windshield wiper motor. When the windshield wiper motor module receives the grounded input, the motor continues to operate until the Hall-effect sensor senses magnetism, which turns off the run/park sense output to the windshield wiper run/park software, deactivating the relay and disconnecting voltage to the wiper motor. The windshield wipers remain parked until the windshield wiper motor module completes a time-out and then repeats the intermittent windshield wiper cycle.

The windshield wiper motor module responds to the windshield wiper control commands by interpreting inputs from the PCM system. The speed dependent wipers will compensate for the extra moisture that accumulates on the windshield at higher speeds, except when the multifunction switch is in the INT 1 position. At higher speeds, the speed dependent feature shortens the delay between wipes when using the variable interval wipers. Delays will automatically adjust at speeds between 16 and 105 km/h (10 and 65 mph).

The windshield washer is activated by the internal wiper motor modules when they receive a ground from the multifunction switch between the washer inputs. Depending on the correct ground, the internal wiper motor module activates the windshield washer relays (internal) by grounding the relay coil. When the relay is activated, it connects voltage to the washer pump, which is grounded through the harness.

The windshield wiper motor defaults to its SOFTWARE SAFE mode when the run/park sensor does not sense the Hall-effect sensor magnet inside the wiper motor. This can be caused by obstruction of windshield wipers or binding linkage. The windshield wiper motor will continue to operate in a HI/LO speed condition for a period of 60 seconds.