The windshield washer solvent heater operates with the standard windshield wiper washer system, and when a heated washer cycle is activated the solvent heater controls the windshield washers through the washer switch signal circuit to the body control module (BCM). The heater is supplied with high current power and ground circuits that are used to energize the heater coils. The low current logic voltage is supplied to the heater through the RUN relay in the underhood fuse block. The RUN relay is a PCB relay energized by the BCM only while the engine is running. The heated washer cycle operation is activated by a separate switch located on the instrument panel accessory switch assembly. When the heated washer fluid switch is pressed the heated washer switch signal circuit is momentarily grounded and the heated washer cycle is activated. During the heated wash cycle the 3 heater elements in the solvent heater are energized, and when the solvent temperature reaches approximately 70°C (160°F) the heater grounds the washer switch signal circuit until the heated solvent is dispensed. The heated washer cycle will run 4 heat and wash actions unless deactivated by the heated washer switch signal.

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

Windshield Washer Solvent Heater Malfunction

1. Ignition OFF, disconnect the X1 harness connector at the windshield washer solvent heater.
2. 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.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.

⇒	If the test lamp does not illuminate, test the B+ voltage circuit for an open/high resistance. If the circuit fuse is open, test the B+ circuit for a short to ground. If the circuit test normal, replace the windshield washer solvent heater.

4. Ignition OFF, connect the X1 harness connector at the windshield washer solvent heater. Disconnect the X2 harness connector at the windshield washer solvent heater.
5. Test for less than 5 ohms between the ground circuit terminal 4 and ground.

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

6. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 6 and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, refer to Power Mode Mismatch.

7. Verify the scan tool Windshield Washer Switch parameter displays Inactive.

⇒	If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, refer to Windshield Wiper Washer System Malfunction.

8. Install a 3A fused jumper wire between the signal circuit terminal 5 and ground. Verify the scan tool Windshield Washer Switch parameter displays 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, refer to Windshield Wiper Washer System Malfunction.

9. Ignition OFF, connect a test lamp between the signal circuit terminal 1 and B+.
10. Command the heated washer system ON and OFF using the heated washer switch. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the signal circuit for a short to ground. If the circuit tests normal, test or replace the headlamp switch.

⇒	If the test lamp is always OFF, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, test or replace the headlamp switch.

11. If all circuits test normal, test or replace the windshield washer solvent heater.

Heated Washer Fluid Indicator Malfunction

1. Ignition OFF, disconnect the X2 harness connector at the windshield washer solvent heater.
2. Ignition ON, install a 3A fused jumper wire between the signal circuit terminal 2 and ground. Verify the heated washer fluid switch indicator is illuminated.

⇒	If the heated washer fluid switch indicator is not illuminated test the signal circuit for a short to voltage or an open/high resistance.

3. If all circuits test normal, test or replace the windshield washer solvent heater.

Heated Washer Fluid Switch

1. Ignition OFF, disconnect the harness connector at the instrument panel accessory switch assembly.
2. Test for infinite resistance between the switch signal circuit terminal and the ground circuit terminal with the switch in the open position.

⇒	If less than infinite, replace the accessory switch assembly.

3. Test for less than 3 ohms between the switch signal circuit terminal and the ground circuit terminal with the switch in the closed position.

⇒	If greater than 3 ohms, replace the accessory switch assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.