2021 GMC Sierra 3500 HD SLT, 6.6L Eng VIN 7, 4WDFACTORY OEM SERVICE PROCEDURE

Replace and Program ECU or Reprogram ECU

To program a replacement or an existing ECU, perform the following procedure:

NOTE:
  • Due to continuous improvements, the on screen selections may vary from instructions below.
  • It is required to program both the B218L Side Object Sensor Module - Left and B218R Side Object Sensor Module - Right when a programming event is required.
  1. Access the Service Programming System (SPS) and follow the on-screen instructions.
  2. On the SPS Supported Controllers screen, select B218L Side Object Sensor Module - Left.
  3. On the SPS Select Function / Sequence screen, select Programming
  4. Clear DTCs.
  5. On the SPS Supported Controllers screen, select B218R Side Object Sensor Module - Right.
  6. On the SPS Select Function / Sequence screen, select Programming
  7. Clear DTCs.
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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