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.
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.
Check out www.fueleconomy.gov
check fuse
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.
A B1440 code on a 2003 Ford Explorer indicates a problem with the vehicle's restraint system, specifically related to the driver's side airbag circuit. This code typically points to issues such as a faulty airbag module, a wiring problem, or a malfunctioning airbag sensor. It's important to diagnose the issue promptly, as it can affect the functionality of the airbag system and overall safety in the event of a collision. A professional diagnostic scan can help pinpoint the exact cause and necessary repairs.
The 2003 Ford Explorer uses R-134a refrigerant for its air conditioning system. It's important to ensure the system is properly serviced and leak-free when using this refrigerant. If you're recharging or repairing the system, make sure to follow manufacturer guidelines for optimal performance.
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.