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.

2008 Hummer H3 AlphaFACTORY OEM SERVICE PROCEDURE

Transfer Case Shift Control Module X2

Fig 1: Transfer Case Shift Control Module X2 Connector End View

Courtesy of GENERAL MOTORS CORP.

Pin	Wire	Circuit	Function
A1-A7	-	-	Not Used
A8	0.35 BK/WH	1554	Low Reference
B1-B5	-	-	Not Used
B6	0.35 D-BU/WH	1557	Channel A Encoder Signal
B7	-	-	Not Used
B8	0.35 GY	596	5-Volt Reference

Connector Part Information

OEM: 12110259
Service: 12110259
Description: 16-Way F Micro-Pack 100 Series (GN)

Terminal Part Information

Terminal/Tray: 12146447/3
Core/Insulation Crimp: E/C
Release Tool/Test Probe: 12031876-1/J-35616-6 (BN)

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:

• 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.