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Home >> GMC >> 2019 >> Terrain SL >> Repair and Diagnosis >> External Pages >> Different car >> Section 81 (Driver Assistance Systems) >> Diagnostic Information And Procedures >> DTC B356A: Vehicle Direction Warning Switch Circuit (GMC) >> Circuit/System Testing
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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. Test for less than 15 ohms between the test points: Ground circuit terminal 10 & Ground
    • If 15 ohms or greater 
    1. Test for less than 2 ohms between the test points: Ground circuit terminal 10 & The other end of the circuit
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Repair the open/high resistance in the ground connection.
    • Go to next step: If less than 15 ohms 
  4. Ignition - On/Vehicle - In Service Mode
  5. Verify the scan tool parameter: Lane Departure Warning Switch = Inactive
    • If not the specified state 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: B174W Frontview Camera - Windshield
    3. Test for infinite resistance between the test points: Signal circuit terminal 10 @ Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component: B174W Frontview Camera - Windshield
    • Go to next step: If the specified state 
  6. Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 13 & Ground
  7. Verify the scan tool parameter: Parking Assist Switch = Active
    • If not the specified state 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    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: Signal circuit terminal 13 @ Component harness & Ground
      • If 1 V or greater - 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: Signal circuit terminal 13 @ Component harness & Terminal 10 @ Control module harness
      • 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
    • Go to next step: If the specified state 
  8. Test or replace the component: S126 Drive Mode Select Switch
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