The 2002 Volkswagen Beetle was available in a GL, GLS, GLX and S sub-model. The available engines were a 1.8-liter turbocharged four-cylinder, 1.9-liter turbo diesel four-cylinder and a 2.0-liter in-line four cylinder. The 2002 Beetle has an onboard diagnostic computer called an OBD-II, which will provide you with the reason your "Check Engine" light is on. The OBD-II monitors several aspects of the engine and emissions, and the "Check Engine" light illuminates when the computer senses a fault in one of the many systems of the car.
Open the driver's door on the Beetle and kneel next to the driver's seat. Locate the OBD-II plug port beneath the dashboard. The OBD-II port looks identical in shape to the plug on the scanner. Insert the scanner plug into the OBD-II port. Sit in the driver's seat of the car when the scanner is connected.
Turn the ignition key to the "II" accessories position without starting the car. Press the power button on the scanner if necessary. Use the arrow keys on the scanner to select your vehicle's type, year, make and model. The 2002 Beetle type is "Foreign." Press the "Read" or "OK" button to accept your answers as you enter them. Choose the "Read trouble codes" selection on the scanner. Allow the scanner to communicate with the car.
Use the information from the scanner to diagnose what part of the vehicle is causing the error code and "Check Engine" light. Your scanner will give you a brief or a long definition, depending on the quality of the scanner software. Some scanners even offer the most popular fixes to eliminate certain codes. Make the repair on the vehicle, or have the repair made by a professional mechanic.
Insert the code reader back into the car after the repairs have been made. Scan the OBD-II computer for codes. Choose the "Erase codes" option. Select "Yes" when the scanner prompts you if you would really like to erase the codes. Allow the scanner to communicate with the car. The scanner will prompt you that there are no remaining codes when the process is finished.
Drive your car as you normally would, if you performed the repairs yourself. If the "Check Engine" light illuminates within a short period of time or immediately, then the proper repairs were not performed. Consult repair manuals and other resources for the repairs to eliminate the "Check Engine" trouble codes you are receiving.
