The check-engine light illuminates when the computer senses something wrong in your Dodge Ram. Several sensors work in harmony to help keep the vehicle running efficiently and smoothly. When there's a problem, a signal is sent to the engine's computer. This activates the check-engine light. There are different codes that correspond to different parts of the engine. This makes diagnosing problems a cinch. Once the problem is fixed, the light can be deactivated.
Loosen the nut that secures the negative connection to the battery. This is the black cable. Remove the cable from the battery.
Wait 20 minutes to allow the computer to reset itself.
Reinstall the battery cable and tighten the nut.
