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Home >> Cadillac >> 2009 >> STS Base, 4.6 A, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Wiper/Washer Systems >> Wiper System And Washer System >> Diagnostic Information and Procedures >> Windshield Wiper System Malfunction >> Circuit/System Testing
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Circuit/System Testing

Multifunction Switch Circuit/System Testing

  1. Ignition OFF, disconnect the X1 harness connector at the turn signal/multifunction switch.
  2. Ignition OFF, test for less than 20.0 ohms resistance between the ground circuit terminal H and ground.
    • If greater than 20.0 ohms check the ground circuit for an open/high resistance. If the circuit tests normal replace the BCM.
  3. Verify the scan tool Windshield Wiper High Speed Switch parameter is Inactive.
    • If not the specified value,test the signal circuit terminal L for a short to ground. If the circuit tests normal, replace the BCM.
  4. Verify the scan tool Wiper High Speed Switch parameter is Inactive.
    • If not Inactive, test the signal circuit terminal K for a short to ground. If the circuit tests normal, test or replace the BCM.
  5. Install a 3A fused jumper wire between the signal circuit terminal L and ground. Verify the scan tool Windshield Wiper Switch parameter is Switch Fault.
    • If not Switch Fault, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal K and ground. Verify the scan tool Wiper High Speed Switch parameter is Active.
    • If not Active, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the BCM
  7. If all circuits test normal, test or replace the turn signal/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 C for a short to ground. If the circuit tests normal, test or replace the body control module.
  3. Install a 3A fused jumper wire between the wiper motor park switch signal circuit terminal C 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, test or replace the windshield wiper motor.

WIPER 1 Relay Control Test

  1. Ignition OFF, disconnect the X5 harness connector at the BCM
  2. Ignition ON, verify that the low speed wipers are not on.
    • If the low speed wipers are on, test the relay control circuit terminal 20 for a short to voltage. If the circuit tests normal, Replace the underhood fuse block.
  3. Install a 10A fused jumper wire between the relay control circuit terminal 20 and B+. Verify the low speed wipers are on.
    • If the low speed wipers are not on, test the relay control circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the underhood fuse block
  4. If all circuits test normal, replace the BCM.

WIPER 2 Relay Control Circuit Test

  1. Ignition OFF, disconnect the X5 harness connector at the BCM
  2. Install a 10A fused jumper wire between B+ and WIPER 1 relay control circuit terminal 20.
  3. Ignition ON, verify that the high speed wipers are not on.
    • If the high speed wipers are on, test the WIPER 2 control circuit terminal 21 for a short to ground. If the circuit tests normal, replace the underhood fuse block.
  4. Install a 10A fused jumper wire between the WIPER 2 relay control circuit terminal 21 and ground. Verify the high speed wipers are on.
    • If the high speed wipers are not on, test the relay control circuit for an open/high resistance or short to voltage. If the circuit tests normal, replace the underhood fuse block.
  5. If all circuits test normal, replace the BCM.

Wiper Motor Circuit Test

  1. Disconnect the harness connector at the windshield wiper motor.
  2. Test for less than 1 ohm between the wiper motor ground circuit terminal 5 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Connect a test lamp between the low speed motor control circuit terminal 1 and ground.
  4. Ignition ON, command the Wiper Relay ON and OFF with a scan tool. 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 underhood fuse block.
    • 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 underhood fuse block.
  5. Connect a test lamp between the high speed motor control circuit terminal 4 and ground.
  6. Wiper switch in the Low position, command the wiper high speed relay ON and OFF with a scan tool. 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 underhood fuse block.
    • If the test lamp is always OFF, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the underhood fuse block.
  7. If all circuits test normal, replace the windshield wiper motor.
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