Pinpoint Test E: The Washer Pump Is Inoperative
Wipers and Washers
Pinpoint Tests
Pinpoint Test E: The Washer Pump is Inoperative
Refer to Wiring Diagram Set 81, Wipers and Washers for schematic and connector information. Diagrams By Number
Normal Operation
When the wash function is selected by the operator, the multifunction switch grounds circuit 680 (LB/OG) to the windshield wiper motor. The windshield wiper motor interprets this ground signal and energizes the internal washer relay. Voltage is sent to the washer pump from the windshield wiper motor through circuit 941 (BK/WH). The windshield washer pump motor is grounded through circuit 57 (BK). The multifunction switch is grounded through circuit 57 (BK).
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Multifunction switch
- Windshield washer pump
- Windshield wiper motor
PINPOINT TEST E: THE WASHER PUMP IS INOPERATIVE
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E1 CHECK THE WASHER PUMP MOTOR FOR VOLTAGE
- Ignition OFF.
- Disconnect: Windshield Washer Pump C137.
- Ignition ON.
- Measure the voltage between windshield washer pump C137-1, circuit 941 (BK/WH), harness side and ground while depressing the multifunction switch to the WASH position.
- Is the voltage greater than 10 volts?
Yes
GO to E2.
No
GO to E3.
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E2 CHECK CIRCUIT 57 (BK) FOR GROUND
- Measure the resistance between the windshield washer pump C137-2, circuit 57 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new windshield washer pump. REFER to Washer Pump and Reservoir Service and Repair.
No
REPAIR the circuit. TEST the system for normal operation.
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E3 CHECK CIRCUIT 941 (BK/WH) FOR AN OPEN
- Ignition OFF.
- Disconnect: Windshield Wiper Motor C125.
- Measure the resistance between windshield wiper motor C125-7, circuit 941 (BK/WH), harness side and windshield washer pump C137-1, circuit 941 (BK/WH), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to E4.
No
REPAIR the circuit. TEST the system for normal operation.
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E4 CHECK THE MULTIFUNCTION SWITCH
- Ignition OFF.
- Disconnect: Multifunction Switch C202b.
- Carry out the Multifunction Switch component test.
- Does the multifunction switch pass the component test?
Yes
GO to E5.
No
INSTALL a new multifunction switch.
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E5 CHECK CIRCUIT 680 (LB/OG) FOR AN OPEN
- Measure the resistance between windshield wiper motor C125-12, circuit 680 (LB/OG), harness side and multifunction switch C202b-2, circuit 680 (LB/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to E6.
No
REPAIR the circuit. TEST the system for normal operation.
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E6 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
INSTALL a new windshield wiper motor. REFER to Wiper Motor Service and Repair.
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.
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