GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

When the transmission is placed into REVERSE, a 12 volt signal is sent to the rearview camera image display module indicating that camera operation is requested. The rearview camera image display module then supplies ignition voltage and ground to the rear vision camera. The rear vision camera sends video information through the rearview camera image display module to the inside rearview mirror through a video signal + and a video signal - circuit. A grounded shielding also wraps the video signal circuits to reduce electronic interference which may degrade the video signal and cause a distorted or otherwise degraded image.

Diagnostic Aids

A poor video image can be caused by ice, snow, and mud buildup on the lens of the rear view camera. Also, extreme lighting conditions can affect performance, such as operating in the dark or with bright sunlight shining on the camera. Extreme high or low temperatures can also affect the image quality. For normal operating characteristics of the rear vision camera system, refer to the Navigation System section of the owners manual.

Reference Information

Schematic Reference

Object Detection Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Object Detection Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Circuit/System Verification

  1. Inspect the rearview camera and verify there are no debris on the lens or that the bezel or bezel seal is not damaged.
  2. If debris are found on the lens, clean the lens. If the lens, bezel, or bezel seal are damaged, replace as necessary.
  3. Ignition ON, vehicle in PARK, verify the backup lamps are off.
  4. If the backup lamps are illuminated, refer to Rear Vision Camera System Always On.
  5. Vehicle in REVERSE, verify a clear rear vision image is displayed on the radio.
  6. If a clear image is not displayed, refer to Rear Vision Camera System Does Not Display.

Circuit/System Testing

Rear Vision Camera System Always On

  1. Ignition OFF, disconnect the harness connector at the rear view camera.
  2. Ignition ON, vehicle in PARK, verify a test lamp does not illuminate between the enable circuit terminal 5 and ground.
  3. If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit test normal, refer to Symptoms - Lighting.
  4. If all circuits test normal, replace the rearview camera.

Rear Vision Camera System Does Not Display

  1. Ignition OFF, disconnect the X1 harness connector at the TV tuner/receiver unit.
  2. Test for less than 1.0 ohm between the ground circuit terminal 3 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp illuminates between the voltage circuit terminal 4 and ground.
  5. If the test lamp does not illuminate, test the voltage circuit for a short to ground or an open/high resistance.
  6. Ignition OFF, connect the harness connector at the TV tuner/receiver unit. Disconnect the harness connector at the rearview camera.
  7. Ignition ON, park brake applied, vehicle in REVERSE, verify that a test lamp illuminates between the enable circuit terminal 5 and ground.
  8. If the test lamp does not illuminate, test the enable circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the TV tuner/receiver unit.
  9. Ignition OFF, test for less than 1.0 ohm between the ground circuit terminal 3 and ground.
  10. If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the TV tuner/receiver unit.
  11. Ignition ON, test for less than 1 volt between the following signal circuits at the rear view camera harness connector and ground:
  12. • Video + signal circuit terminal 2
    • Video - signal circuit terminal 1
    If less than the specified range, test the video circuit for an open/high resistance. If the circuit tests normal, replace the TV tuner/receiver unit.
  13. Test for infinite resistance between the following signal circuits at the rear view camera harness connector and ground:
  14. • Video + signal circuit terminal 2
    • Video - signal circuit terminal 1
    If less than the specified value, test the signal circuit for a short to ground.
  15. If all circuits test normal, replace the rearview camera.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rearview Camera Replacement
    •  Control Module References for rear view camera image display module or inside rearview mirror replacement, setup, and programming