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 ground through the control circuit to the coil side of the WS WASH relay energizing the relay. With the relay energized, battery voltage is applied through the switch contacts of the relay, the WSW fuse, and the control circuit to the windshield washer fluid pump.

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

Scan Tool Reference

Control Module References for Scan Tool Information

Washers Inoperative Starting Point

Ignition ON, with a test lamp connected to ground, probe each of the test points on the WSW fuse while activating the Windshield Washer Switch. The test lamp should illuminate at one or both of the fuse test points.

Washer Switch Test

1. Ignition ON, observe the scan tool Windshield Washer Switch parameter while pressing the Washer Switch. The reading should change between Inactive and Active.

⇒	If not Active, test the following:

•	Perform the multifunction switch component test.

•	Test the windshield washer switch signal circuit for an open/high resistance. If the washer switch and circuit test normal, test or replace the body control module.

2. Ignition OFF, disconnect the X2 harness connector at the underhood fuse block.
3. Connect a test lamp between the washer relay control circuit terminal H6 and battery voltage.
4. 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.

⇒	If the test lamp is always OFF, test the control circuit terminal H6 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the body control module.

5. If all circuits test normal, test or replace the underhood fuse block.

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 B and ground.

⇒	If greater than 1 ohm, repair the ground circuit for an open/high resistance.

3. Connect a test lamp between the washer pump control circuit terminal A and ground.
4. 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.

⇒	If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the underhood fuse block.

5. If all the circuits test normal, test or replace the windshield washer fluid pump.

Washers Always On

1. Remove the WSW fuse from the underhood fuse block. The washer pump should turn OFF.

⇒	If the washer pump does not turn OFF, repair the short to voltage on the washer pump control circuit.

2. Ignition ON, verify the scan tool Windshield Washer Switch parameter is Inactive.

⇒	If not Inactive, test the following:

•	Perform the multifunction switch component test.

•	Test the windshield washer switch signal circuit for a short to ground. If the washer switch and circuit test normal, replace the body control module.

3. Ignition OFF, disconnect the X2 harness connector at the underhood fuse block.
4. Ignition ON, verify that a test lamp does not illuminate between the windshield washer relay control circuit terminal H6 and battery voltage.

⇒	If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the body control module.

5. If all circuits test normal, test or replace the underhood fuse block.

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.

⇒	If the resistance is not within the specified range, replace the turn signal/multifunction switch.

3. Test for infinite resistance with the wiper switch in the High speed position.

⇒	If less than infinite ohms, replace the turn signal/multifunction switch.

4. Test for infinite resistance between terminals H and K while rotating the wiper switch to MIST, each DELAY and LOW speed positions.

⇒	If the less than infinite, replace the turn signal/multifunction switch.

5. Test for less than 5 ohms of resistance with the wiper switch in the High speed position..

⇒	If greater than 5 ohms, replace the turn signal/multifunction switch.

6. Test for infinite resistance between terminals H and J while rotating the wiper switch to MIST, each DELAY and LOW speed positions.

⇒	If less than infinite, replace the turn signal/multifunction switch.

7. Test for less than 5 ohms of resistance while pressing the WASHER switch.

⇒	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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.