Diagnostic Procedure

2001 Chevrolet Chevy Express G2500, Van Cargo Extended, 5.7 R, L31/KL8SECTION Diagnostic Procedure
WARNING: This page is about a different variant/trim than selected.
  1. Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing powertrain diagnostic system check, go to next step.
  2. Check IGN 1 fuse, located in instrument panel fuse block for "C" & "K" series, or GAUGES fuse, located in instrument panel fuse block for "G" series. If fuse is open, go to step  10. If fuse is not open, go to next step.
  3. Turn ignition off. Disconnect PCM. Turn ignition on, engine off. Connect a fused jumper wire (3-amp) between PCM Red connector C2 terminal No. 46 (Brown/White wire) and ground. See Fig 1. Observe MIL. If MIL illuminates, go to step  9. If MIL does not illuminate, go to next step.
  4. If fuse in jumper wire opened, go to step  11. If fuse in jumper wire did not open, go to next step.
  5. Remove Instrument Panel Cluster (IPC). See appropriate ANALOG INSTRUMENT PANELS article. Check Brown/White wire between PCM and IPC for open. If problem was found, repair as necessary. After repairs, go to step  14. If problem was not found, go to next step.
  6. Using a test light connected to ground, probe IPC connector terminal B6 (Pink wire) for "C" and "K" series and terminal B17 (Pink wire) for "G" series. See Fig 2 or Fig 3 . If test light is on, go to step  8. If test light is off, go to next step.
  7. Repair open in Pink wire between IPC and fuse block. After repairs, go to step  14.
  8. Check IPC connector for poor connections. If problem was found, repair as necessary. After repairs, go to step  14. If problem was not found, go to step  12.
  9. Check PCM connectors for poor connections. If problem was found, repair as necessary. After repairs, go to step  14. If problem was not found, go to step  13.
  10. Repair short to ground in Pink wire between IPC and fuse block. After repairs, go to step  14.
  11. Repair short to voltage in Brown/White wire between IPC and PCM. After repairs, go to step  14.
  12. Replace IPC. See appropriate ANALOG INSTRUMENT PANELS article. After repairs, go to step  14.
  13. Replace PCM. Program PCM. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After repairs, go to next step.
  14. Operate system to verify repair.
Fig 1: Identifying Powertrain Control Module Connectors C1 & C2 Terminals
G97E28443Courtesy of GENERAL MOTORS CORP.
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When to See a Mechanic

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

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