The engine symbol light on the 2004 Honda Pilot is better known as the check engine light. The light is an indication of a failure or irregularity in the computer-controlled engine control system. When the computer receives and recognizes an irregular or lost signal from either a sensor or operational device, it responds by designating a description code for the error and illuminating the check engine light as a notification.
Plug the code scanner into the OBD (on board diagnostic) port located under the driver's side of the dash, just to the left of the steering column. Turn the ignition key to the run position---all the warning lights will be illuminated on the dash---but do not start the engine.
Press the "Read" button on the code scanner. Record the code displayed on the code scanner and cross-reference the code with the code decipher sheet. The sheet will give an explanation of the code, pinpointing the problem device and what was found irregular. Turn the ignition off.
Make the repair so the code can be cleared, which is the only way to reset the light.
Turn the ignition switch to the run position and press the "Erase" button. The code scanner will erase the code in the computer and turn the check engine light off. The light will remain off if the repair was done properly or until another problem presents itself.
