The Honda Accord's engine management system keeps track of any error codes triggered by any of the connected sensors. When a problem has been detected, the error code is stored in the computer, which prompts the engine light to turn on. The code can then be read with a code reader, pinpointing the exact location of the problem and ensuring an easier fix. After the issue has been repaired, the light will stay turned on until it has been manually cleared.
Remove the nut from the negative black cable and wiggle the cable free. Place a piece of cardboard between the cable and the battery to ensure it doesn't spring back into place.
Press and hold the brake pedal for several seconds. This activates the tail lights, draining any remaining power from the electrical system.
Wait at least five minutes to give the computer time to fully reset. Reverse the process to replace the battery cable. Remove the cardboard.
Start the engine. The engine light will now be reset. If it turns back on, that means the original problem has not been resolved, causing the computer to trigger the error code again.
Be careful not to cause a dangerous short-circuit by accidentally touching the battery cables together.