GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    â€¢ Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    â€¢ Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    â€¢  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 Signal

2

1

3

--

Windshield Washer Pump Control

1

1

2

--

Windshield Washer Relay Control

2

1

B3873 00

--

Windshield Washer Pump Ground

--

1

--

--

Windshield Wiper Switch Ground

--

3

--

--

1. Washers Inoperative

2. Washers Always On

3. Windshield Wiper System Malfunction

Circuit/System Description

The windshield washer function is controlled by the body control module (BCM). When the washer switch is pressed, ground is applied through the switch contacts and the signal circuit to the BCM indicating the wash request. The BCM then applies battery voltage through the control circuit to the windshield washer fluid pump.

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

    â€¢  Circuit Testing
    â€¢  Connector Repairs
    â€¢  Testing for Intermittent Conditions and Poor Connections
    â€¢  Wiring Repairs

Scan Tool Reference

Control Module References for Scan Tool Information

Circuit/System Testing

Washer Switch Test

  1. Ignition OFF, disconnect the X3 harness connector at the turn signal multifunction switch.
  2. Ignition OFF test for less than 20 ohms between the low reference circuit terminal H and ground.
  3. ⇒If greater than the specified range, test the low reference circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool Windshield Washer Switch parameter is Inactive.
  5. ⇒If not the specified value, test the signal circuit terminal J for a short to ground. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal J and the low reference circuit terminal H. Verify the scan tool Windshield Washer Switch parameter is Active.
  7. ⇒If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  8. If all circuits test normal, test or replace the turn signal multifunction switch.

Washer Fluid Pump Test

  1. Ignition OFF, disconnect the harness connector at the windshield washer fluid pump.
  2. Test for less than 1 ohm of resistance between the ground circuit terminal 2 and ground.
  3. ⇒If greater than the specified range test the ground circuit for an open/high resistance.
  4. Connect a test lamp between the washer pump control circuit terminal 1 and ground.
  5. Ignition ON, command the Wiper Washer Motor ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
  6. ⇒If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the BCM.
  7. If all the circuits test normal, test or replace the windshield washer fluid pump.

Component Testing

Multifunction Switch

  1. With the ignition OFF, disconnect the X3 harness connector at the turn signal/multifunction switch.
  2. Test the resistance between terminals H and L. Rotate the wiper switch and compare the resistance readings to the values in the Windshield Wiper Switch Values table below for MIST, each DELAY and LOW speed.
  3. ⇒If the resistance is not within the specified range, replace the turn signal/multifunction switch.
  4. Test for infinite resistance with the wiper switch in the High speed position.
  5. ⇒If less than infinite ohms, replace the turn signal/multifunction switch.
  6. Test for infinite resistance between terminals H and K while rotating the wiper switch to MIST, each DELAY and LOW speed positions.
  7. ⇒If the less than infinite, replace the turn signal/multifunction switch.
  8. Test for less than 5 ohms of resistance with the wiper switch in the High speed position..
  9. ⇒If greater than 5 ohms, replace the turn signal/multifunction switch.
  10. Test for infinite resistance between terminals H and J while rotating the wiper switch to MIST, each DELAY and LOW speed positions.
  11. ⇒If less than infinite, replace the turn signal/multifunction switch.
  12. Test for less than 5 ohms of resistance while pressing the WASHER switch.
  13. ⇒If greater than 5 ohms, replace the turn signal/multifunction switch.

Important: If the switch tests open in any switch position other than Off, test the wiper/washer switch signal circuits for a short to voltage before replacing the switch.

Wiper Switch Values

Switch Position

Resistance

Off

Infinite

Mist

300-364 Î©

Delay 1

3.48K-4.25K Î©

Delay 2

2.52K-3.08K Î©

Delay 3

1.78K-2.18K Î©

Delay 4

1.17K-1.44K Î©

Delay 5

697-851 Î©

Low

2.52K-3.08K Î©

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    â€¢  Windshield Wiper Motor Replacement
    â€¢  Washer Pump Replacement
    â€¢  Control Module References for BCM replacement, setup, and programming