Open the driver's side door on the 2003 Buick and locate the diagnostic link connector (DLC) underneath the dashboard. On a LeSabre and Park Avenue, the DLC is located under the dash to the left of the steering column. On the Century and Rendezvous models, Launch X431 the DLC is under the dash directly beneath the steering column. On the Buick Regal, the DLC is located under the dash to the right of the steering column.

Plug the OBD II scanner/eraser into the DLC. Because of the DLC's shape and the shape of the plug, there is only one correct way to plug it in.

Place the key of the Buick into the ignition and turn the key to the accessory power position. OBDSTAR Scanner This position illuminates the lights on the instrument cluster and powers all the accessory components without the engine running. It will also provide power to the scanner from the Buick's battery.

Press the erase button on the faceplate of the scanner. If the scanner is not equipped with an erase button, Auto Key Programmer follow the onscreen menu and use the scroll or enter button(s) to the erase codes or DTCs option and press the enter button.

Allow the onscreen menu of the scanner to default back to its main menu or display a "command sent" message.

Start the engine to the Buick and check the instrument cluster to ensure the SEL is no longer displayed. If it still is on or comes back quickly, the code(s) should be diagnosed properly and repairs made if necessary.