Circuit/System Testing

2009 Chevrolet Tahoe Base, 4.8 CSECTION Circuit/System Testing

Right Side Object Sensor Malfunction

  1. Ignition OFF, disconnect the harness connector at the right side object sensor.
  2. Test for less than 5 Ω between the ground circuit terminals listed below and ground:
    • Terminal 5
    • Terminal 6
    • If greater than the specified range, test the appropriate ground circuit for an open/high resistance.
  3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. If all circuits test normal, replace the right side object sensor.

Left Side Object Sensor Malfunction

  1. Ignition OFF, disconnect the harness connector at the left side object sensor.
  2. Test for less than 5 Ω between the ground circuit terminal 5 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Ignition OFF, disconnect the harness connector at the right side object sensor.
  5. Ignition ON, test for less than 1 V between the serial data circuit terminal 4 and ground.
    • If greater than the specified range, test the serial data circuit for a short to ground.
  6. Test for infinite resistance between the serial data circuit terminal 4 and ground.
    • If not the specified value, test the serial data circuit for a short to ground.
  7. Test for less than 2 Ω between the serial data circuit terminal 4 at the left side object sensor harness connector and the serial data circuit terminal 4 at the right side object sensor harness connector.
    • If greater than the specified range, test the serial data circuit for an open/high resistance.
  8. If all circuits test normal, replace the left side object sensor.

Side Object Indicator Malfunction

  1. Ignition OFF, disconnect the X2 harness connector at the outside rearview mirror.
  2. Connect a test lamp between the control circuit terminal 4 and the low reference circuit terminal 1.
  3. Ignition ON, verify the test lamp briefly illuminates during the system self test.
    • If the test lamp does not illuminate or remains illuminated at all time, test the control circuit and the low reference circuit for a short to voltage, short to ground, or an open/high resistance. If the circuits test normal, replace the appropriate door module.
  4. If all circuits test normal, test or replace the appropriate outside rearview mirror.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.