Circuit/System Testing

Multifunction Switch Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the windshield wiper/washer switch.
2. Ignition ON, test for B+ at the windshield wiper/washer 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 wiper/washer switch.

Windshield Wiper Motor Circuit Malfunction

1. Ignition OFF, disconnect wiper 1 relay.
2. Test for less than 20 Ω between the ground circuit terminal 86 and ground.
   • If greater than the specified range, test the ground circuit for an open/high resistance.
3. Test for less than 20 Ω 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 85 and the ground circuit terminal 86.
6. Using the wiper/washer 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 WIPER 2 relay.
8. Test for less than 2 Ω between the control circuit terminal 30 at the WIPER 2 relay and the control circuit terminal 30 at the WPR 1 relay.
   • If greater than the specified range, replace the underhood fuse block.
9. Connect the WPR 1 relay.
10. Test for less than 20 Ω between the control circuit terminal 30 and ground.
    • If greater than the specified range, test or replace the WIPER 1 relay.
11. Test for less then 20 Ω between the ground circuit terminal 85 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
12. Install a test lamp between the control circuit terminal 30 and the ground circuit terminal 85.
13. Using the wiper/washer switch, command the low speed wipers ON. The test lamp should turn illuminate.
    • If the test lamp does not illuminate, replace the WIPER 1 relay.
14. Install a test lamp between the ground circuit terminal 85 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 wiper/washer switch.
    • 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 wiper/washer switch.
16. Ignition OFF, connect the WIPER 2 Relay. Disconnect the harness connector at the windshield wiper motor.
17. Test for less than 20 Ω between the ground circuit terminal C 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 E and ground.
19. Using the wiper/washer 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 WIPER 2 relay.
    • 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 WIPER 2 relay.
20. Connect a test lamp between the control circuit terminal D 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 WIPER 2 relay.
    • 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 WIPER 2 relay.
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.