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 Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Transfer Case Shift Control Module Scan Tool Information
WARNING: This page is about a different car, the 2009 GMC Canyon and 2009 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
Scan Tool Output Controls
| Output Control | Description |
|---|---|
| Refer to the scan tool manual for complete scan tool operating instructions. | |
| 2WD High Indicator Light | This function allows the technician to command the 2WD high indicator light, within the accessory switch, on or off. |
| 4WD High Indicator Light | This function allows the technician to command the 4WD high indicator light, within the accessory switch, on or off. |
| 4WD Low Indicator Light | This function allows the technician to command the 4WD low indicator light, within the accessory switch, on or off. |
| ATC Motor A Control | This function allows the technician to energize the motor, causing it to shift the transfer case through all five modes. |
| Engage Front Axle | This function allows the technician to engage and disengage the front axle actuator. When the front axle actuator is engaged, the front axle becomes a live axle, causing the front propshaft to turn. |
| Neutral Indicator Light | This function allows the technician to command the neutral indicator light, within the accessory switch, on or off. |
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.