LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> GMC >> 2019 >> Terrain SL >> Repair and Diagnosis >> External Pages >> Different car >> Section 81 (Driver Assistance Systems) >> Diagnostic Information And Procedures >> DTC B0987: Vehicle Direction Camera Indicator Circuit (GMC) >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

WARNING: This page is about a different car, the 2018 GMC Terrain and 2018 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
    NOTE:

    It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: S126 Drive Mode Select Switch
  3. Connect a test lamp between the test points: Control circuit terminal 1 & B+
  4. NOTE:

    Verify interior lighting dimming is turned all the way up.

  5. Perform the scan tool control function: Lane Departure Warning Indicator Command - On and Off

    Verify the test lamp turns On and Off.

    • If the test lamp is always Off 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: @ B174W Frontview Camera - Windshield
    3. Ignition - On/Vehicle - In Service Mode
    4. Test for less than 1 V between the test points: Control circuit terminal 4 @ B174W Frontview Camera - Windshield & Ground
      • If greater than 1 V

        Repair the short to voltage on the circuit.

      • If less than 1 V
    5. Ignition/Vehicle - Off
    6. Test for less than 2 ohms between the test points: Control circuit terminal 4 @ B174W Frontview Camera - Windshield & Control circuit terminal 1 @ S126 Drive Mode Select Switch
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component: B174W Frontview Camera - Windshield
    • If the test lamp is always On 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: @ B174W Frontview Camera - Windshield
    3. Test for infinite resistance between the test points: Control circuit terminal 4 @ B174W Frontview Camera - Windshield & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component: B174W Frontview Camera - Windshield
  6. Test or replace the component: S126 Drive Mode Select Switch