Circuit/System Testing

Multifunction Switch Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the windshield wiper washer multifunction switch.
2. Ignition ON, test for B+ at the windshield wiper washer multifunction switch Accessory Voltage circuit terminal D
   • If not the specified value, test the Accessory Voltage circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the BCM.
3. Ignition ON, verify the scan tool Windshield Wiper Switch parameter is Off.
   • If not the specified value, test the Windshield Wiper Switch Signal 1 circuit terminal E for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3A fused jumper wire between the Windshield Wiper Switch Signal 1 circuit terminal E and B+. Verify the scan tool Windshield Wiper Switch parameter is Low/Mist/High.
   • If not the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
5. Install a 3A fused jumper wire between the Windshield Wiper Switch Signal 2 circuit terminal C and ground. Verify the scan tool Windshield Wiper Switch parameter Low/Mist/High.
   • 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.
6. If all circuits test normal, test or replace the Multifunction Switch.

Wipers Do Not Park Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the windshield wiper motor.
2. Ignition ON, verify the scan tool BCM Wiper Park Switch parameter is Inactive.
   • If not Inactive, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the body control module.
3. Install a 3-amp fused jumper wire between the wiper motor park switch signal circuit terminal B and ground. Verify the scan tool Wiper Park Switch parameter is Active.
   • If not Active, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the body control module.
4. If all circuits test normal, replace the windshield wiper motor.

Windshield Wiper Motor Circuit Malfunction

1. Ignition OFF, disconnect WPR Relay 70.
2. Test for less than 20 ohms of resistance between the ground circuit terminal 85 and ground.
   • If greater than the specified range, test the ground circuit for an open/high resistance.
3. Test for less than 20 ohms of resistance between the ground circuit terminal 87A and ground.
   • If greater than the specified range, test the ground circuit for an open/high resistance.
4. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 87 and ground.
   • If the test lamp does not illuminate, test or replace the underhood fuse block.
5. Install a test lamp between the control circuit terminal 86 and the ground circuit terminal 85.
6. Using the multifunction switch, command the low speed wipers ON and OFF. The test lamp should turn ON and OFF as commanded.
   • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
   • 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, replace the BCM.
7. Ignition OFF, disconnect the WPR Relay 52.
8. Test for less than 2 ohms of resistance between the control circuit terminal 30 at the WPR relay and the control circuit terminal 30 at the WPR HI relay.
   • If greater than the specified range, replace the underhood fuse block.
9. Connect the WPR Relay 52.
10. Test for less than 20 ohms of resistance between the control circuit terminal 30 and ground.
    • If greater than the specified range, test or replace the WPR Relay 52.
11. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 85 and ground.
    • If the test lamp does not illuminate, test or replace the underhood fuse block.
12. Install a test lamp between the control circuit terminal 30 and the ground circuit terminal 87.
13. Using the multifunction switch, command the low speed wipers ON. The test lamp should turn illuminate.
    • If the test lamp does not illuminate, replace the WPR Relay 52.
14. Install a test lamp between the B+ circuit terminal and the control circuit terminal 86.
15. Using the multifunction switch, command the high speed wipers ON and OFF. The test lamp should turn ON and OFF as commanded.
    • 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.
16. Ignition OFF, connect the WPR Relay 52. Disconnect the harness connector at the windshield wiper motor.
17. Test for less than 20 ohms of resistance between the ground circuit terminal A and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
18. Connect a test lamp between the control circuit terminal D and ground.
19. Using the multifunction switch, command the low speed wipers ON and OFF. The test lamp should turn ON and OFF as commanded.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the WPR Relay 70.
    • 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 WPR Relay 70.
20. Connect a test lamp between the control circuit terminal C and ground.
21. Using the multifunction switch, command the high speed wipers ON and OFF. The test lamp should turn ON and OFF as commanded.
    • If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the WPR Relay 52.
    • 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 WPR Relay 52.
22. Verify a test lamp illuminates between the signal circuit terminal B and ground.
    • If the test lamp does not illuminate, replace the BCM.
23. If all circuits test normal, test or replace the windshield wiper motor.