How do you reset the service engine soon light on a mercury mountaineer

l think only the mechanic can do it. It might be running low on some fluids, or sometimes high sulfur content in the gas, but l think the mechanic has to decide it for you.

TAKE IT TO AUTO PALACE THEY WILL RESET IT FOR YOU AND THEY WILL TELL IF THERE ANY CODES TO BE FOUND. OR JUST TAKE OFF THE NEG. CABLE FOR 15 SECONDS AND IT WILL RESET IT BUT IT WILL COME BACK ON IF THERE ARE ANY CODES..

l wish we both knew l had mine changed and the service men did not know either.they followed the instructions in the owners manual but it did not work

Disconnect the battery for 20 minutes. If the light comes back on then you know there is a problem. Sometimes if you let your car run while getting gas will cause this.

On ANY vehicle, if the ''check engine or ''service engine soon'' light illuminates, it means the vehicle is PCM (powertrain control module) has stored a DTC (diagnostic trouble code). Yes, it is true that u can disconnect the battery for a few seconds to ''reset'' it, as others have posted. But, if there is a problem, that light will only come back on shortly after. You have one of a few options. You can take ur vehicle to either the dealer (more costly, but preferable option), or an automotive technician WITH GOOD ELECTRICAL AND DRIVEABILITY DIAGNOSTIC SKILLS, to retrieve & DIAGNOSE the cause of the DTC, & let u make the decision to repair, or not repair the concern. OR, u can take ur vehicle to Auto Zone (or BOZO ZONE as l like to refer to them as), have them run their ''FREE'' diagnosis, & tell u what the DTC is (which will be as good as telling u to read Chinese, unless u have an understanding of the meaning behind the DTCs). If the latter of the two options is what u choose, DO NOT let them try to sell u a part. They r NOT automotive technicians. You get what u pay for. Hope this helps.

when you are on your way to the dealer to trade that pos in, stop close by somewhere, disconected the battery, wait 15 mins, reconnect the battery then you will have a very short drive to the dealership where they can appraise it and not see the engine light;)