Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 GMC Sierra 3500 HD SLT, 6.6L Eng VIN 7, 4WDFACTORY OEM SERVICE PROCEDURE
Programming a New Control Module - Old Module Communicates
- Ignition - On / Vehicle - In Service Mode
- Access SPS and follow the on-screen instructions for the control module: K69 Transfer Case Control Module
- Perform the SPS function: K69 Transfer Case Control Module - Prepare Control Module for Removal
- Replace the component: K69 Transfer Case Control Module
- Perform the SPS function: K69 Transfer Case Control Module - Programming
- Perform the SPS function: K69 Transfer Case Control Module - Setup
Verify the Transfer Case Clutch Identifieris auto populated correctly, if incorrect enter the correct Transfer Case Clutch Identifier.
Refer to: Transfer Case Identification
- Clear DTCs.
- Perform the scan tool function: Range Actuator Learn
Refer to: Transfer Case Range Actuator Learn
Factory Service Tools
Use the Manual With the Right Hardware
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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.