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Circuit/System Testing

WARNING: This page is about a different car, the 2013 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

Multifunction Switch Circuit Malfunction

  1. Ignition OFF, disconnect the X1 harness connector at the multifunction switch.
  2. Ignition OFF, test for less than 80 Ω between the ground circuit terminal 2 and ground.
    • If greater than the specified range, test the ground 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 1 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 3 for a short to ground. If the circuit tests normal, replace the BCM.
  5. Install a 3 A fused jumper wire between the signal circuit terminal 1 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 3 A fused jumper wire between the signal circuit terminal 3 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 multifunction switch.

Windshield Wiper Motor Circuit Malfunction

  1. Ignition OFF, disconnect WPR relay.
  2. Test for less than 5 Ω 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 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 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 HI relay.
  8. Test for less than 2 Ω 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.
  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 WPR 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. 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.
  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 HI relay. Disconnect the harness connector at the windshield wiper motor.
  17. Test for less than 20 Ω between the ground circuit terminal 5 (with LHD) or 4 (with RHD) 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 1 (with LHD) or 5 (with RHD) 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 HI 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 WPR HI relay.
  20. Connect a test lamp between the control circuit terminal 4 (with LHD) or 3 (with RHD) 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 HI 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 WPR HI relay.
  22. If all circuits test normal, test or replace the windshield wiper motor.

Wipers Do Not Park

  1. Ignition OFF, disconnect the harness connector at the windshield wiper motor.
  2. Test for less than 5 Ω between the ground terminal 2 and ground.
    • If greater than the specified value, test the circuit for an open/high resistance.
  3. Verify the scan tool parameter Wiper Park Switch is Inactive
    • If not the specified value, test the signal circuit terminal 3 (with LHD) or 1 (with RHD) for a short to ground. If the circuit tests normal, replace the BCM.
  4. Install a 3 A fused jumper wire between the signal circuit terminal 3 (with LHD) or 1 (with RHD) and the ground circuit terminal 2. Verify the scan tool parameter Wiper Park Switch 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.
  5. If all circuits test normal, test or replace the windshield wiper motor.
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