Circuit/System Verification

Ignition - On / Vehicle - In Service Mode
Verify that no DTCs are set.
- If any DTC is set
  Refer to:Diagnostic Trouble Code (DTC) List - Vehicle
- Go to next step: If no DTC is set
Verify the component turns On and Off:Lane Departure Warning Indicator
- Lane Departure Warning Switch
- If the component does not turn On and Off
  Refer to:DTC B0987 (GMC) , or DTC B0987 (Chevrolet)
- Go to next step: If the component turns On and Off
All OK.