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.
Circuit/System Verification
2021 GMC Terrain SLT, 4WDSECTION Circuit/System Verification
- Verify the battery cable connections are clean and tight and verify battery voltage is between 12.0 - 15.0 V measured at the battery terminals.
- If not within the specified range
Refer to Battery Inspection/Test
- Go to next step: If within the specified range
- If not within the specified range
- Verify the customer has the Proactive Alert SAC004 from OnStar, or by using the Scan Tool "Vehicle Diagnostics" - "Vehicle Proactive Alerts", or Service Workbench Alerts.
- If Proactive Alert SAC004 is present.
Refer to Circuit/System Testing.
- Go to next step: If Proactive Alert SAC004 is not present.
- If Proactive Alert SAC004 is present.
- All OK.
RENDER: 1.0x
NO RELATED
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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.