Principles of Operation
The windshield wiper motor receive inputs from the following:
- multifunction switch
- lighting control module (LCM)
- ignition switch
- battery junction box (BJB)
- central junction box (CJB)
The following components are integrated into the windshield wiper motor:
- windshield wiper motor module
- high/low speed relay
- run/park sensor (Hall effect)
- washer pump relay
High Speed Windshield Wipers
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 sensor and high/low relay coil, activating the relay with voltage supplied from the ignition switch (RUN/ACC) 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 senses the magnet in the motor. When the Hall effect senses the magnet in 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 Windshield Wipers
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.
Intermittent Speed Windshield Wipers
The intermittent 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 Hall effect sensors senses the wiper motors magnet, which turns off the run/park sensor 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.
Washer System
The windshield washer is activated by the internal wiper motor module when it receives a ground from the multifunction switch between the washer input. Dependent on the correct ground, the internal wiper motor modules activates the windshield washer relay (internal) by grounding the respective relay coil. When the relay is activated, it connects voltage to the washer pump while the washer level switch provides ground to the washer pump.
Default Mode
The windshield wiper motor defaults to this mode when the run/park sensor does not sense the hall effect magnet inside wiper motor. This can be caused by obstruction of the windshield wipers or a binding linkage. The windshield wiper motor will continue to operate in a high/low speed condition for a period of 60 seconds.
Symptom Chart
Symptom Chart
Condition
Possible Sources
Action
- The wipers are inoperative
- Multifunction switch
- Circuitry
- Ignition switch
- Windshield wiper motor
Do you know how to test automotive electrical circuits using a factory diagnostic test procedure flow chart ?
PINPOINT TEST A: THE WIPERS ARE INOPERATIVE
Test Step
Result / Action to Take
A1 CHECK CIRCUITS 65 (DG) AND 2025 (RD/YE) FOR VOLTAGE
- Key in OFF position.
- Disconnect: Windshield Wiper Motor C125.
- Key in ON position.
- Measure the voltage between windshield wiper C125 pin 5, circuit 2025 (RD/YE), harness side and ground; and between windshield wiper motor C125 pin 8, circuit 65 (DG), harness side and ground.
- Are the voltages greater than 10 volts?
Yes
GO to A2 .
No
REPAIR the circuit(s) in question. TEST the system for normal operation.
A2 CHECK CIRCUITS 57 (BK) AND 676 (PK/OG) FOR OPENS
- Key in OFF position.
- Measure the resistance between windshield wiper C125 pin 6, circuit 57 (BK), harness side and ground; and between windshield wiper motor C125 pin 3, circuit 676 (PK/OG), harness side and ground.
- Are the resistances less than 5 ohms?
Yes
GO to A3 .
No
REPAIR the circuit(s) in question. TEST the system for normal operation.
A3 CHECK THE MULTIFUNCTION SWITCH
- Disconnect: Multifunction Switch C202b.
- Carry out the multifunction switch component test.
Refer to Wiring Diagrams Cell 149 for schematic and connector information.
- Does the multifunction switch pass the component test?
Yes
GO to A4 .
No
INSTALL a new multifunction switch. REFER to Section 211-05 .
A4 CHECK CIRCUIT 57 (BK) FOR AN OPEN
- Measure the resistance between C202b pin 5, circuit 57 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to A5 .
No
REPAIR the circuit. TEST the system for normal operation.
A5 CHECK CIRCUITS 56 (DB/OG), 58 (WH), 61 (YE/RD), AND 63 (RD) FOR OPENS
- Using the following table, measure the resistance between the multifunction switch C202b harness side and the windshield wiper motor C125 harness side:
Multifunction Switch C202b
Windshield Wiper Motor C125
pin 6, circuit 56 (DB/OG)
pin 10, circuit 56 (DB/OG)
pin 3, circuit 58 (WH)
pin 11, circuit 58 (WH)
pin 1, circuit 61 (YE/RD)
pin 1, circuit 61 (YE/RD)
pin 4, circuit 63 (RD)
pin 9, circuit 63 (RD)
- Are the resistances less than 5 ohms?
Yes
GO to A6 .
No
REPAIR the circuit(s) in question. TEST the system for normal operation.
A6 CHECK FOR CORRECT WIPER MOTOR OPERATION
- Disconnect all wiper motor connectors.
- Check for:
- corrosion
- pushed-out pins
- Connect all wiper motor connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
GO to A7 .
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.
A7 CHECK THE WINDSHIELD WIPER MOTOR
- Key in OFF position.
- Disconnect: Windshield Wiper Motor C125.
- Carry out the windshield wiper motor component test as outlined in this section.
- Does the windshield wiper motor pass the component test?
Yes
The system is operating correctly at this time. The concern may have been caused by binding or incorrect pivot arm adjustment. REFER to Windshield Wiper Blade and Pivot Arm Adjustment in this section. TEST the system for normal operation.
No
INSTALL a new windshield wiper motor. REFER to Windshield Wiper Motor in this section.
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