Battery positive voltage is supplied to the coil and switch sides of the headlamp washer relay. The body control module (BCM) energizes the relay by grounding the relay coil through the relay control circuit. When the relay is energized, the relay switch is closed and battery positive voltage is supplied to the washer pump control circuit.

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Headlamp Washer System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Verify headlamps are turned on.
2. Ignition ON, observe the scan tool Headlamp Washer Relay Command parameter while pressing and releasing the windshield washer switch. The reading should change between On and Off.

⇒	If not the specified value, refer to Multifunction Switch Circuit Test.

3. If the switch input to the BCM functions normal refer to Headlamp Washer Pump Circuit Test.

Windshield Washer Switch

1. Ignition OFF, disconnect the X1, harness connector at the multifunction switch.
2. Test for less than 1.0 ohm between the ground circuit terminal 2 and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance, if the circuit tests normal , replace the BCM..

3. Ignition ON, verify the scan tool Headlamp Wash parameter is Off.

⇒	If not the specified value, test the signal circuit terminal 4 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 4 and the ground. Verify the scan tool Headlamp Wash parameter is On.

⇒	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 multifunction switch.

Headlamp Washer Pump Circuit Test

1. Ignition OFF, disconnect the HEADLAMP WPR relay.
2. Ignition ON, verify that a test lamp does not illuminate between the washer pump control circuit terminal 87 and ground.

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

3. Disconnect the harness connector at the headlamp washer pump.
4. Test for less than 5.0 ohms between the headlamp washer pump ground circuit terminal B and ground.

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

5. Connect the harness connector at the headlamp washer pump.
6. Connect a 20A fused jumper wire between the B+ circuit terminal 30 and the washer pump control circuit terminal 87. Verify the headlamp washer pump is activated.

⇒	If the headlamp washer pump does not activate, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the headlamp washer pump.

7. Connect a test lamp between the B+ circuit terminal 86 and the relay control circuit terminal 85.
8. Operate the headlamp washer switch ON and OFF. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the relay 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.

9. If all circuits test normal, test or replace the HEADLAMP WPR relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.