How to Reset the Service Engine Soon Light on a 2002 Lincoln Town Car

The 2002 Lincoln Town Car warning indicator "Service Engine Soon" light warns of a problem with one of the vehicle's emission control systems. When the light shines solid it can indicate temporary problems caused by a loose fuel cap, low quality or contaminated fuel or no fuel in the tank. When it is blinking you should not drive the car as it indicates a mechanical problem causing the engine to misfire. You should stop the vehicle immediately to prevent damage and additional problems. Lincoln outlines a few steps to clear a solid light but you will need an On Board Diagnostic (OBD) II reader to clear a flashing, or solid, light.

Lincoln Recommends

• 1

  Fill the vehicle with uncontaminated 87 octane fuel of 87. If you suspect the original fuel is contaminated, use a different gas station.

• 2

  Replace the gas cap. Make sure the seal is tight and that there is no damage to the gas cap that could prevent a proper seal.

• 3

  Drive the vehicle for three full driving cycles. A driving cycle includes a cold engine start and a mix of city and highway driving. If the fuel or the cap's seal were the source of the problem, the light should turn off after three driving cycles.

OBD II Reader

• 1

  Locate the Town Car's Data Link Connector (DLC). The DLC joins the OBD II readers to the car's diagnostic computer system. This system provides error codes correlating to the problem found that is triggering the "Service Engine Soon" light. This enables a mechanic to easily troubleshoot the problem for repair. The DLC is under the dash, below and to the right of the steering wheel.

• 2

  Turn the Town Car's ignition key to the "On" position. You do not need to start the car, but turning the key to the "On" position powers the Town Car's diagnostic computer system. Plug the OBD II reader's connector into the DLC. Turn on the OBD II reader power if it needs power.

• 3

  Follow the OBD II reader's instructions to retrieve error codes from the Town Car. Compare these codes to the ones listed on the Ford OBD Trouble Codes (See Resources). If the problem triggering the error code is not fixed, the "Service Engine Soon" light will continue to be triggered. Resetting the light will only be a temporary solution and will not fix the underlying problem.

• 4

  Follow your OBD II reader's instructions to erase existing error codes and reset the system. Readers will have varying methods of clearing error codes. These include pressing an "Erase Codes" button and going through menu options. Disconnect the OBD II reader once finished.

• 5

  Turn the Town Car ignition key to the "Off" position and then start the car. If the "Service Engine Soon" light is still lit, repeat the above steps. If the light is still lit after repeating the steps, this indicates a problem with the system diagnostic controller.