Circuit/System Testing

Windshield Wiper/Washer Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the Windshield Wiper/Washer Switch Malfunction.
2. Ignition OFF, test for less than 20 ohms between the low reference circuit terminal B and ground.
   • If greater than the specified range, test the low reference circuit for 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 signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM.
4. Verify the scan tool Wiper High Speed Switch parameter Inactive.
   • If not the specified value, test the signal circuit terminal C for a short to ground. If the circuit tests normal, replace the BCM.
5. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool Windshield Wiper Switch parameter is Switch Fault.
   • 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. Install a 3A fused jumper wire between the signal circuit terminal C and ground. Verify the scan tool Wiper High Speed 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.
7. If all circuits test normal, test or replace the Windshield Wiper/Washer Switch Malfunction.

Windshield Wiper Motor Circuit Malfunction

1. Ignition OFF, disconnect WIPER relay.
2. Test for less than 20 ohms 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 ohms 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. Ignition ON, command the WIPER relay 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 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 HIGH relay.
8. Test for less than 2 ohms between the control circuit terminal 30 at the WIPER relay and the control circuit terminal 30 at the WIPER HIGH relay.
   • If greater than the specified range, replace the underhood fuse block.
9. Connect the WIPER relay.
10. Test for less than 20 ohms between the control circuit terminal 30 and ground.
    • If greater than the specified range, test or replace the WIPER relay.
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 ground.
13. Ignition ON, command the WIPER relay ON. The test lamp should turn illuminate.
    • If the test lamp does not illuminate, replace the WIPER relay.
14. Install a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.
15. Ignition ON, command the WIPER HIGH relay ON and OFF. The test lamp should turn ON and OFF when changing between 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.
16. Ignition OFF, connect the WIPER HIGH relay. Disconnect the harness connector at the windshield wiper motor.
17. Test for less than 20 ohms between the ground circuit terminal 2 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 4 and ground.
19. Ignition ON, command the WIPER relay 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 control circuit for a short to voltage. If the circuit tests normal, test or replace the WIPER HIGH 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 HIGH relay.
20. Connect a test lamp between the control circuit terminal 3 and ground.
21. Ignition ON, command the WIPER HIGH 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 control circuit for a short to voltage. If the circuit tests normal, test or replace the WIPER HIGH 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 HIGH relay.
22. Wipers OFF, verify a test lamp illuminates between the signal circuit terminal 1 and ground.
    • If the test lamp does not illuminate, test the signal circuit for a short to ground or an open high resistance. If the circuit tests normal, replace the BCM.
23. If all circuits test normal, test or replace the windshield wiper motor.