Circuit/System Testing

2012 Chevrolet Chevy Express G2500, Van Passenger, 4.8L Eng VIN ASECTION Circuit/System Testing
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  1. Ignition OFF, disconnect the R6 IGN relay and connect a test lamp between the relay control circuit and ground.
  2. Cycle the ignition ON and OFF. The test lamp should turn ON and OFF when changing ignition switch positions.
    • If the test lamp remains OFF all the time, test for a short to ground or an open/high resistance on the relay control circuit. If the circuit tests normal, replace the BCM.
    • If the test lamp remains ON all the time, test for a short to voltage on the relay control circuit. If the circuit tests normal, replace the BCM.
  3. If test lamp turns ON and OFF normal, test or replace the R6 IGN relay.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.