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 WSW relay energizing the relay. With the relay energized, B+ from the WSW fuse is applied through the switch contacts of the relay 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

1. Ignition ON, wiper switch OFF, observe the scan tool Windshield Washer Switch parameter while cycling the washer switch ON and OFF. The parameter should change between Active and Inactive.

⇒	If the parameter does not cycle between the specified values, refer to Windshield Washer Switch Malfunction.

2. Operate the washers using the washer switch. Verify the washer pump activates and the low speed wipers turn on.

⇒	If the washer pump does not activate, refer to Washer Pump Circuit Malfunction.

⇒	If the low speed wipers do not turn on refer to Windshield Wiper System Malfunction

Windshield Wiper/Washer Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the windshield wiper/washer switch.
2. Test for less than 40 Ω between the low reference circuit terminal 8 and ground.

⇒	If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit test normal, replace the BCM.

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

⇒	If not the specified value, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal 6 and ground. Verify the scan tool Windshield Washer Switch parameter is Active.

⇒	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.

5. If all circuits test normal, test or replace the windshield wiper/washer switch.

Washer Pump Circuit Malfunction.

1. Ignition OFF, disconnect the WSW relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 30 and ground.

⇒	If the test lamp illuminates, test the control circuit for a short to voltage.

3. Verify that a test lamp illuminates between the B+ circuit terminal 87 and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open high/resistance.

4. Verify a test lamp illuminates between the B+ circuit terminal 86 and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open high/resistance.

5. Disconnect the harness connector at the windshield washer fluid pump.
6. Ignition OFF, test for less than 5 ohms between the ground circuit terminal 2 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

7. Connect the harness connector at the windshield washer fluid pump.
8. Connect a 15A fused jumper wire between the B+ circuit terminal 87 and the control circuit terminal 30. Verify the windshield washer fluid pump is activated.

⇒	If the windshield washer fluid pump does not activate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the windshield washer fluid pump.

9. Connect a test lamp between the B+ circuit terminal 86 and the control circuit terminal 85.
10. Command the windshield washer fluid pump 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 ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.

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

11. If all circuits test normal, test or replace the WSW Relay.

Windshield Washer Switch

1. Ignition OFF, disconnect the harness connector at the windshield wiper/washer switch.
2. With the wash switch in the Open position, test for infinite resistance between the low reference terminal 8 and the signal terminal 6.

⇒	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 low reference terminal 8 and the signal terminal 6.

⇒	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 1 and 12 volts. Install a jumper wire between the ground terminal 2 and ground.
3. Verify the washer pump is activated.

⇒	If the washer pump does not activate , replace the washer pump.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.