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Home >> Cadillac >> 2019 >> CTS Base, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 130 (Image Display Camera System) >> Diagnostic Information and Procedures >> Rearview Camera Full Display Mirror Malfunction >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2018 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF/vehicle OFF, disconnect the X1 harness connector at the A10 Inside Rearview Mirror.
  2. Test for less than 10 Ω between the A10 Inside Rearview Mirror ground circuit terminal 5 X1 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.
    • Go to next step: If less than 10 Ω 
  3. Ignition ON.
  4. Verify a test lamp illuminates between the ignition circuit terminal 2 X1 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 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is OK and there is voltage at the fuse. Refer to Power Mode Mismatch .
    • 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 A10 Inside Rearview Mirror.
    • Go to next step: If the test lamp illuminates 
  5. Ignition OFF/vehicle OFF, connect the X1 harness connector at the A10 Inside Rearview Mirror.
  6. Disconnect the coax cable connector at the A10 Inside Rearview Mirror and wait for 5 sec..
  7. Ignition On/Vehicle in Service Mode, test for 7 - 11 V at the A10 Inside Rearview Mirror.
    • If the value outside range of 7 - 11V 

      Test or replace the A10 Inside Rearview Mirror.

    • Go to next step: If the value within the range of 7 - 11 V 
  8. Ignition OFF/vehicle OFF, connect the coax cable connector at the A10 Inside Rearview Mirror.
  9. Disconnect the coax cable connector at the B87 Rearview Camera, and wait for 5 sec.
  10. Ignition On/Vehicle in Service Mode, test for 7 - 11 V between the center conductor of the coax cable and the coax cable ground shield wires.
    • If the value within the range of 7 - 11 V 

      Replace the B87 Rearview Camera.

    • Go to next step: If the value outside range of 7 - 11V 
  11. Replace the coax cable.
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