Circuit/System Testing

2006 Chevrolet Chevy Express G2500, Van Cargo, 6.6 2SECTION Circuit/System Testing
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  1. Ignition ON, observe the scan tool BCM Battery Voltage parameter. The reading should be equal to B+ voltage.
    • If not the specified value, test the following BCM circuits for an open/high resistance. If the circuits test normal, replace the BCM.
      • B+ circuit terminal 3 X3
      • Ground circuit terminal 1 X3
      • Ground circuit terminal 5 X3
      • Ground circuit terminal 9 X4
  2. Verify that the current sensor is mounted correctly on the negative battery cables. The sensor should be installed with the internal coil around the negative battery cables, with the tape tab pointing away from the battery.
    • If the sensor is not installed correctly, remove and reinstall the sensor.
  3. Ignition OFF, disconnect the harness connector at the battery current sensor.
  4. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 ohms between the low reference circuit terminal B and ground.
    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
  5. Ignition ON, test for 4.5-5.5 volts between the 5-volt reference circuit terminal A and ground.
    • If not within the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  6. Ignition ON, test for 4.5-5.5 volts between the signal circuit terminal C and ground.
    • If not within the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  7. If all circuits test normal, replace the battery current sensor.
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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.