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Home >> Cadillac >> 2014 >> SRX Performance, AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Wiper/Washer Systems >> Wiper System And Washer System >> Diagnostic Information and Procedures >> DTC B370B: Rear Wiper Function Control Circuit >> Circuit/System Testing
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Circuit/System Testing

Rear Wiper/Washer Switch Malfunction

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S82 Windshield Wiper/Washer Switch. It may take up to 11 min for all vehicle systems to power down.
  2. Test for less than 10 Ω between the low reference circuit terminal 2 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the low reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
    • If less than 10 Ω 
  3. Ignition ON.
  4. Test for greater than 8 V between the signal circuit terminal 4 and ground.
    • If less than 8 V 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the signal circuit and ground
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
    • If 8 V or greater 
  5. Ignition OFF, disconnect the X2 harness connector at the K9 Body Control Module, ignition ON.
  6. Test for less than 1 V between the S82 Windshield Wiper/Washer Switch signal circuit terminal 4 and ground.
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • If less than 1 V 
  7. Test or replace the S82 Windshield Wiper/Washer Switch.

Rear Wiper Motor Malfunction

  1. Ignition OFF, and all vehicle systems OFF. Disconnect the harness connector at the M45 Rear Wiper Motor. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10 Ω between the ground circuit terminal C and ground.
    • If 10 Ω or greater 
    1. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 10 Ω 
  3. Ignition ON.
  4. Verify a test lamp illuminates between the B+ circuit terminal B and the ground circuit terminal C.
    • If the test lamp does not illuminate 
    1. Ignition OFF, remove the test lamp. Disconnect the X1 harness connector at the X50A Fuse Block - Underhood.
    2. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the X50A Fuse Block - Underhood.
    • If the test lamp illuminates 
  5. Connect a test lamp between the control circuit terminal A and the ground circuit terminal C.
  6. Verify the test lamp does NOT turn ON and OFF when commanding the Rear Wiper On and Off with a scan tool.
    • If the test lamp turns ON and OFF 

      Test or replace the M45 Rear Wiper Motor.

    • If the test lamp does NOT turn ON and OFF 
  7. Ignition OFF, connect the harness connector at the M45 Rear Wiper Motor. Disconnect the X1 and X2 harness connectors at the X50A Fuse Block - Underhood, It may take up to 2 min for all vehicle systems to power down.
  8. Test for less than 10 Ω between each ground circuit terminal listed below and ground:
    • Terminal 15 X1
    • Terminal 27 X2
    • If 10 Ω or greater 
    1. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 10 Ω 
  9. Ignition ON.
  10. Verify the M45 Rear Wiper Motor is NOT activated.
    • If the M45 Rear Wiper Motor is activated 
    1. Ignition OFF, disconnect the harness connector at the M45 Rear Wiper Motor, ignition ON.
    2. Test for less than 1 V between the control circuit terminal A and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the M45 Rear Wiper Motor.
    • If the M45 Rear Wiper Motor is not activated 
  11. Connect a 20 A fused jumper wire between both of the circuits listed below and B+.
    • Terminal 36 X1
    • Terminal 7 X1
  12. Verify the M45 Rear Wiper Motor activates.
    • If the M45 Rear Wiper Motor does not activate 
    1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the M45 Rear Wiper Motor, ignition ON.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than Infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the M45 Rear Wiper Motor.
    • If the M45 Rear Wiper Motor activates 
  13. Ignition OFF, connect the X1 and X2 harness connectors at the X50A Fuse Block - Underhood. Disconnect the X4 harness connector at the K9 Body Control Module, ignition ON.
  14. Verify the M45 Rear Wiper Motor is not activated.
    • If the M45 Rear Wiper Motor is activated 
    1. Ignition OFF, disconnect the X1 harness connector at the X50A Fuse Block - Underhood, ignition ON.
    2. Test for less than 1 V between the control circuit terminal 13 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the X50A Fuse Block - Underhood.
    • If the M45 Rear Wiper Motor is not activated 
  15. Connect a 10 A fused jumper wire between the control circuit terminal 10 and B+.
  16. Verify the M45 Rear Wiper Motor activates.
    • If the M45 Rear Wiper Motor does not activate 
    1. Ignition OFF, remove the jumper wire, disconnect the X2 harness connector at the X50A Fuse Block - Underhood.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If less than infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, test or replace the X50A Fuse Block - Underhood.
    • If the M45 Rear Wiper Motor activates 
  17. Test or replace the K9 Body Control Module.
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