B3903 Code – Stop Lamp Relay Circuit Short

What are the Possible Causes of the Code B3903?
  • Faulty Stop Lamp Relay
  • Stop Lamp Relay harness is open or shorted
  • Stop Lamp Relay circuit poor electrical connection
  • Faulty Body Control Module (BCM)
  • Need help with this OBD II code? Our mechanics are available within west Michigan to help. Outside of our service area? Visit our Car Help Section where you can ask questions and get answers.

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