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.
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HOMESERVICE MANUALSGMC2021SIERRA 2500 HD AT4, 6.6L ENG VIN 7REPAIR AND DIAGNOSISACCESSORIES & EQUIPMENTSTEERING COLUMN SWITCHESSECONDARY AND CONFIGURABLE CUSTOMER CONTROLSDIAGNOSTIC INFORMATION AND PROCEDURESDRIVE MODE SWITCH MALFUNCTIONCIRCUIT/SYSTEM VERIFICATION
2021 GMC Sierra 2500 HD AT4, 6.6L Eng VIN 7
Circuit/System Verification
2021 GMC Sierra 2500 HD AT4, 6.6L Eng VIN 7SECTION Circuit/System Verification
- Ignition - On / Vehicle - In Service Mode
- Operate the component:S126 Drive Mode Select Switch - Rotate Left & Rotate Right - Multiple Buttons Pressed
Verify the following information is correctly displayed:Drive Mode @ A5 Driver Information Center
- If the component does not work as specified
Refer to: Circuit/System Testing - Test 1
- Go to next step: If the component works as specified
- If the component does not work as specified
- All OK.
RENDER: 1.0x
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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.