1. Turn the ignition key to the "ON" position, but do not start the engine.
* Do not press the gas pedal.
2. Locate the diagnostic connector under the hood of your Galant.
* It is usually located near the battery or fuse box.
* On your 2003 Galant GTZ, it is behind the fuse box cover in the engine bay.
* It has a black plastic cover with a red or orange button.
3. Press and hold the red or orange button on the connector.
* Keep holding the button until the Service Engine Soon light starts to flash (about 5-10 seconds).
4. Release the button and turn the key to the "OFF" position.
5. Wait a few seconds and then turn the key to the "ON" position (do not start the engine).
* The Service Engine Soon light should now be reset and turned off.
Note: If the Service Engine Soon light is still on after following these steps, it may indicate a more serious problem with the vehicle that requires professional diagnosis and repair.
* In that case, it is recommended to take your Galant to a qualified mechanic for further inspection.
