Circuit/System Testing

2011 Chevrolet Chevy Express G3500, Van Cargo Extended, 6.6 LSECTION Circuit/System Testing
NOTE:

You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Connect a test lamp between each fuse test terminal of the ignition switch B+ circuit fuse and ground. The test lamp should illuminate.
    • If the test lamp does not illuminate, test the circuits listed below for a short to ground. If all circuits test OK, replace the BCM.
    • B+ terminal 4
    • Ignition terminal 2
    • Ignition terminal 3
    • Ignition terminal 5
    • Ignition voltage terminal BCM terminal 21, X4
  2. Disconnect the harness connector at the ignition switch.
  3. Connect a test lamp between the B+ circuit terminal 4 and ground. The test lamp should illuminate.
    • If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.
  4. NOTE:

    The ignition switch component test must be performed before proceeding with this test to verify the integrity of the switch.

  5. Perform the ignition switch component test. Verify the switch passes the test.
    • If the ignition switch does not test normal, replace the ignition switch.
  6. Disconnect the X 1 harness connector at the BCM, test for less than 1.0 V between the following ignition circuit terminals of the BCM and ground.
    • terminal 2
    • terminal 4
    • terminal 14
    • terminal 21
    • If greater than specified, test the circuit for a short to voltage.
  7. Test for less than 1.0 Ξ© between the BCM and the ignition switch on the ignition circuits listed below:
    • terminal 2, X1 and ignition switch terminal 5
    • terminal 4, X1 and ignition switch terminal 6
    • terminal 14, X1 and ignition switch terminal 2
    • terminal 21, X1 and ignition switch terminal 3
    • If greater than specified, test the circuit for open/high resistance
  8. If all circuits test normal, replace the BCM.
RENDER: 1.0x

NO RELATED

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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.