2001 GMC C3500 HD 8.1 G, AutomaticFACTORY OEM SERVICE PROCEDURE

Installation Procedure

    Fig 1: PCM Mounting Hardware And Harness Connectors
    GM334905Courtesy of GENERAL MOTORS COMPANY
  1. Install the PCM (4) to the PCM mounting bracket (7) ensuring that the mounting tabs (3) are engaged.
  2. Secure the spring latch (2) to the PCM.
  3. Refer to Fastener Notice in Cautions and Notices.

    Connect the PCM connectors (6) to the PCM (4).

    TightenΒ 

    Tighten the PCM connector end bolts to 8 N.m (71 lb in).

  4. Install the PCM cover (8) to the PCM mounting bracket (7), ensuring the mounting tabs on the PCM mounting bracket are engaged into the mounting holes in the PCM cover.
  5. If a new PCM is being installed, program the EEPROM. Refer to Powertrain Control Module Programming (On-Board)Β , Powertrain Control Module Programming (Off-Board)Β .
Factory Service Tools

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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.

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