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 StandardFACTORY OEM SERVICE PROCEDURE
Service Programming Methods
The 4 methods of programming a PCM and the proper tools for each method are as follows:
- Remote Programming. See SERVICE PROGRAMMING SYSTEM REMOTE PROCEDURE .
- Pass Thru Programming. See SERVICE PROGRAMMING SYSTEM PASS-THRU PROCEDURE .
- Off-Board Remote Programming, vehicle NOT available. See SERVICE PROGRAMMING SYSTEM OFF BOARD REMOTE PROCEDURE .
- Off-Board Pass Thru Programming. See SERVICE PROGRAMMING SYSTEM OFF BOARD PASS-THRU PROCEDURE .
Factory Service Tools
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.