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Home >> Cadillac >> 2017 >> ATS Base, 4D Sedan, RWD, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 174 (Cellular System, Entertainment System, And Navigation System - Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> DTC B128B: Video Display Output Signal - Signal Amplitude >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2016 Cadillac CT6. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF.
  2. Verify the LVDS interface cable is properly connected at the appropriate P22 Video Display and the A33 Media Disc Player and there is no damage to the cable or connections.
  3. Ignition ON, infotainment system ON.
  4. Verify the P22 Video Display does display an image with rear seat entertainment sourced to front display.
    • If the P22 Video Display does not display an image. 
    1. Ignition OFF.
    2. Replace the video interface cable.
    3. Ignition ON, infotainment system ON.
    4. Verify the P22 Video Display does display an image.
      • If the P22 Video Display does not display an image
    5. Replace the P22 Video Display. Connect all harness connectors.
    6. Ignition ON, infotainment system ON.
    7. Verify the P22 Video Display does display an image.
      • If the P22 Video Display still does not display an image, replace the A33 Media Disc Player.
      • If the P22 Video Display does display an image.
    8. All OK.
    • If the P22 Video Display does display an image. 
  5. All OK.
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