2003 Buick Century BaseFACTORY OEM SERVICE PROCEDURE

30 Minute Learn Procedure

  1. Turn ignition switch to RUN position, engine OFF.
  2. Attempt to start the engine, then release the key to RUN position (vehicle will not start).
  3. Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
  4. Turn ignition switch to OFF position, and wait 5 seconds.
  5. Repeat steps  1- 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the password on the next ignition switch transition from OFF to CRANK position).
    6. NOTE: The vehicle learns the password on the next ignition switch transition from OFF to CRANK. You must turn the ignition switch to OFF position before attempting to start the vehicle.
  6. Start the engine (the vehicle has now learned the password).
  7. Using a scan tool, clear any DTCs if needed (history DTCs will self clear after 100 ignition cycles).
Factory Service Tools

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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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