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Home >> Buick >> 2013 >> Encore Convenience, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 96 (Object Detection System And Pedestrian Protection System) >> Diagnostic Information and Procedures >> DTC B127B: Rearview Camera Input Signal Circuit Missing Reference (Trax) >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2016 Chevrolet Trax and 2016 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:

Circuit/System Verification must be performed before Circuit/System Testing.

  1. Ignition OFF, disconnect the harness connector at the B87 Rearview Camera.
  2. Test for less than 10 Ω between the ground circuit terminal 4 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    2. 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 ignition circuit terminal 5 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the ignition circuit end to end.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF.
    2. Test for infinite resistance between the ignition circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the B87 Rearview Camera.
    • If the test lamp illuminates 
  5. Ignition OFF, disconnect the X1 harness connector at the All Radio, ignition ON.
  6. Test for less than 1 V between the signal circuit terminal listed below and ground:
    • B87 Rearview Camera signal (+) circuit terminal 15
    • B87 Rearview Camera signal (-) circuit terminal 14
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • If less than 1 V 
  7. Test for infinite resistance between the signal circuit terminal listed below and ground:
    • B87 Rearview Camera signal (+) circuit terminal 15
    • B87 Rearview Camera signal (-) circuit terminal 14
    • If less than infinite resistance 

      Repair the short to ground on the circuit.

    • If infinite resistance 
  8. Test for less than 2 Ω between the A11 Radio signal (+) circuit terminal 15 X1 and the B87 Rearview Camera signal (+) circuit terminal 1.
    • If 2 Ω or greater 

      Repair the open/high resistance in the circuit.

    • If less than 2 Ω 
  9. Test for less than 2 Ω between the A11 Radio signal (+) circuit terminal 14 X1 and the B87 Rearview Camera signal (+) circuit terminal 2.
    • If 2 Ω or greater 

      Test the signal circuit for an open/high resistance.

    • If less than 2 Ω 
  10. Replace the B87 Rearview Camera.
  11. Engine running, transmission in R, verify a clear rear vision image is displayed on the P17 Info Display Module.
    • If a clear rear vision image is not displayed 

      Replace the All Radio.

    • If a clear rear vision image is displayed 
  12. All OK.
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