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
- Vehicle in Service Mode, verify no OnStar DTC's are set.
- If any OnStar DTC's are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- If no OnStar DTC's are set
- If any OnStar DTC's are set
- Verify the scan tool Telematics Communication Interface Control Module/Data Display/GPS Data/Second parameter is incrementing.
- If seconds are not incrementing
- If seconds are incrementing
- Replace the K114B Hybrid/EV Powertrain Control Module 2.
The vehicle needs to be in an open, outside area where a cellular call can be successfully placed and GPS data can be received from satellites.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.
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