The check engine light in a vehicle takes varying amounts of time to reset based on the method chosen to reset it. The best way to reset a check engine light is to repair the problem that's causing the light to be on.
Using a check engine light code reader can let the car owner understand what caused the check engine light. Code readers are available for purchase online to use at home. Alternatively, taking the vehicle to an auto parts store or garage where a technician can read the codes and offer advice and assistance can reveal the cause of the check engine light. Disconnecting the battery from the vehicle, draining the remaining stored electricity in the system and reattaching the battery resets the check engine light temporarily but the light is likely to come back on as soon as the computer recognizes the problem again.