If I'm understanding this correctly, the owner's manual states to press the setup button, then press the system check /or reset for sys check button It will then cycle through each of the systems being monitored displaying either OK or a warning message for 3 seconds.
A check engine light informs you that there is something wrong with the engine. After you run a diagnostic test, you will be able to tell what exactly is wrong.
check fuse
Check out www.fueleconomy.gov
I'm not sure if Mercury followed Ford with the introduction of the new HVAC system in 2003. That is probably the case and the system and problems will be the same as the Ford Explorer. Pictures to identify which system you have and diagnostic processes are available on heatertreater.net.
It should , my 1995 Explorer XLT does
A leak somewhere in your Vacuum System.
It should be.
You have to use VAG-COM diagnostic computer (Audi, VW, Skoda, Seat) plug it into diagnostic pluge and change it in the computer menu.
Check all your grounds
One of hundreds of things. It means that something in the emissions system is getting a bad reading. The only way to know what it is specifically, is to read the codes stored with a diagnostic tester.
My 2005 will do that if the gas cap was not secured tightly.
how to remove the spare on a 2003 explorer