GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Windshield Washer Switch Ignition Voltage

1

1

--

--

Windshield Washer Fluid Pump Control

2

1

--

--

Windshield Washer Fluid Pump Ground

--

1

--

--

1. Washer Inoperative

2. Washers Always ON

Circuit/System Description

During windshield wiper/washer system WASH operation the wiper motor module controls the operating voltage to the wiper motor and the windshield washer pump. The WASH switch contact closes the wiper/washer switch accessory voltage supply circuit to the low circuit. Accessory voltage on the low circuit indicates to the wiper motor module the WASH command is active. When the wiper motor module activates the WASH function, the wiper motor accessory voltage supply circuit is closed to the wiper motor low speed terminal and the windshield washer pump control circuit for a minimum of 3.5 seconds or as long as the WASH command is active followed by 2 wiper motor cycles.

Reference Information

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Wiper/Washer System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Turn ignition ON, operate the windshield washer switch. The washers should operate normally and low speed wipers should wipe  3 to  5 times for a mist washer cycle.

Circuit/System Testing

Windshield Wiper/Washer Switch Circuit Malfunction

  1. Ignition OFF, disconnect the X201 harness connector at the Windshield Wiper/Washer Switch.
  2. Ignition ON, test for 12 volts between accessory voltage circuit terminal  E4 and ground.
  3. If not the specified value, test the accessory voltage circuit for a short to ground or open/high resistance.
  4. Ignition OFF, reconnect the harness connector at Windshield Wiper/Washer Switch. Disconnect the harness connector at the windshield wiper motor.
  5. Ignition ON, test for B+ at accessory voltage circuit terminal  B.
  6. If not the specified value, test the accessory voltage circuit for a short to ground or open/high resistance.
  7. Test for B+ at Low/Pulse/Delay signal circuit terminal D while washer switch is being activated.
  8. If not the specified value, test the Low/Pulse/Delay signal circuit for a short to ground or open/high resistance. if all the circuits test normal replace the Windshield Wiper/Washer switch
  9. Test for B+ at the High Speed Control circuit terminal  C with the windshield wiper switch in the high speed position.
  10. If not the specified value, test the High Speed Control circuit for a short to ground or open/high resistance. if all the circuits test normal replace the Windshield Wiper/Washer switch

Washer Pump Circuit Malfunction

  1. Ignition OFF, Disconnect harness connector at Windshield Washer Fluid Pump.
  2. Ignition ON, test for B+ at control circuit termina l  A of Windshield Washer Fluid Pump connector.
  3. If not the specified value, test the controll circuit for a short to ground or an open/high resistance.
  4. Install a test light between control circuit terminal  A and ground circuit terminal  B at the windshield washer fluid pump connector
  5. The test lamp should turn ON and OFF when the windshield washers are commanded ON and OFF.
  6. If not the specified value, test the ground circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the windshield wiper washer switch.

Component Testing

Windshield Wiper Washer Switch

  1. With the WASH switch in the open position, test for infinite resistance between the Accessory Voltage terminal  E4 and the control terminal  E5.
  2. If not the specified value, replace the windshield wiper washer switch.
  3. With the WASH switch in the closed position, test for less than 2 ohms between the Accessory Voltage terminal  E4 and the control terminal  E5.
  4. If greater than the specified range, replace the windshield wiper washer switch.

Washer Pump

  1. Ignition OFF, disconnect the harness connector at the washer pump.
  2. Install a 10A fused jumper wire between the control terminal  A and 12 volts. Install a jumper wire between the ground terminal  B and ground.
  3. Verify the washer pump is activated.
  4. If the washer pump does not activate , replace the washer pump.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Turn Signal Multifunction Switch Replacement
    •  Windshield Washer Solvent Container and Pump Replacement