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.
2003 Pontiac Sunfire AutomaticFACTORY OEM SERVICE PROCEDURE
Service Programming System: Notes
After replacing PCM or if program needs to be updated, refer to latest Techline information on PCM reprogramming. Before programming a PCM, the following must be observed, or PCM damage may occur:
- The Tech 2 and the terminal must have the latest software.
- The vehicle battery must be fully charged. The battery voltage should be 12-14 volts.
- The Tech 2 and the terminal cable connections must be secure.
- A battery charger must NOT be connected to the battery when programming a PCM.
Factory Service Tools
Use the Manual With the Right Hardware
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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.