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Home >> Cadillac >> 2017 >> CTS Base, AWD >> Repair and Diagnosis >> Accessories & Equipment >> Drivers Assistance Systems - ADAS >> Object Detection System And Pedestrian Protection System >> Diagnostic Information and Procedures >> DTC B399B: Rearview Camera Supply Circuit Short >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF, disconnect the B87 Rearview Camera harness connector. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10 Ω between the low reference circuit terminal 5 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF, disconnect the harness connector at the K157 Video Processing Control Module.
    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 K157 Video Processing Control Module.
    • If less than 10 Ω 
  3. Ignition ON.
  4. Test for 4.8-7.2 V between the 6 V reference circuit terminal 6 and ground.
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the harness connector at the K157 Video Processing Control Module.
    2. Test for infinite resistance between the 6 V reference 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 6 V 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 K157 Video Processing Control Module.
    • If greater than 7.2 V 
    1. Ignition OFF, disconnect the harness connector at the K157 Video Processing Control Module, ignition ON.
    2. Test for less than 1 V between the 6 V reference circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K157 Video Processing Control Module.
    • If between 4.8-7.2 V 
  5. Ignition ON.
  6. Test for less than 10 V between the signal circuit terminals listed below and ground:
    • Vision Signal + signal circuit terminal 1
    • Vision Signal - signal circuit terminal 4
    • If 10 V or greater 
    1. Ignition OFF, disconnect the X1 harness connector at the K157 Video Processing Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K157 Video Processing Control Module.
    • If less than 10 V 
  7. Ignition OFF.
  8. Test for greater than 100 Ω between the signal circuit terminals listed below and ground:
    • Vision Signal + signal circuit terminal 1
    • Vision Signal - signal circuit terminal 4
    • If less than 100 Ω 
    1. Disconnect the X1 harness connector at the K157 Video Processing Control Module.
    2. Test for infinite between the signal circuit and ground.
      • If less than infinite resistance, repair the short to voltage on the circuit.
      • If infinite resistance, replace the K157 Video Processing Control Module.
    • If greater than 100 Ω 
  9. Test for less than 2 Ω between the video signal circuit terminals listed below:
    • B87 Rearview Camera video signal (+) circuit terminal 1 and the K157 Video Processing Control Module video signal (+) circuit terminal 4 X1
    • B87 Rearview Camera video signal (+) circuit terminal 4 and the K157 Video Processing Control Module video signal (+) circuit terminal 14 X1
    • If 2 Ω or greater 

      Repair the open/high resistance in the circuit.

    • If less than 2 Ω 
  10. Ignition OFF, connect the harness connector at the B87 Rearview Camera.
  11. Ignition ON, clear DTCs. Operate the vehicle within the Conditions for Running the DTC.
  12. Verify DTC B399B is not set.
    • If DTC B399B is set 

      Replace the B87 Rearview Camera.

    • If DTC B399B is not set 
  13. All OK.
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