LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Buick >> 2021 >> Envision Preferred, AWD >> Repair and Diagnosis >> Accessories & Equipment >> Drivers Assistance Systems - ADAS >> Driver Assistance Systems >> Diagnostic Information and Procedures >> DTC B13AD >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

  1. Ignition OFF, disconnect the connector at the S48E Floor Console Accessory Function Switch.
  2. Verify a test lamp illuminates between ground circuit terminal 1 and B+
    • If the test lamp does not illuminate 

      Repair the open/high resistance on circuit 1751 or the ground connection.

    • Go to next step: If the test lamp illuminates 
  3. Ignition ON.
  4. Verify the scan tool Lane Departure Warning Switch Status parameter is Off.
    • If the parameter is not Off 
    1. Test circuit 3153 for a short to ground.
      • If a short to ground is found, repair the fault on the circuit.
      • Go to next step: If a short to ground is not found
    2. Replace the K9 Body Control Module.
    • Go to next step: If the parameter is Off 
  5. Connect a 3 A fused jumper wire between signal circuit terminal 16 and ground.
  6. Verify the scan tool Lane Departure Warning Switch Status parameter is On.
    • If the parameter is not On 
    1. Test circuit 3153 for an open/high resistance.
      • If an open/high resistance is found, repair the fault on the circuit.
      • Go to next step: If a short to ground is not found
    2. Replace the K9 Body Control Module.
    • Go to next step: If the parameter is On 
  7. Replace the S48E Floor Console Accessory Function Switch.