I had the same problem, and since I couldn't find the answer here, I had to figure it out myself. Luckily, I was able to find this site again, so here's what worked for me.
Push the Setup button three times, until your driver display says something like "Press Reset for system check".
Then push Reset. The system check will start, rotating through a series of checks.
About the fifth or sixth check will be the tire pressure. It'll say something like "Hold Reset if tires are OK". While that's up, hold the Reset button. After 3 or 4 seconds, the tire warning light will click off. You need to be ready for it, because you don't get very long.
Sorry if I don't have the prompts exactly right. I remembered them the best I could, and since I held in the Reset button, I don't get the one about the tires being OK any more.
How to reset the low tire pressure warning if the vehicle does not have the "Message Center"
Ah, the aux plug in a 2004 Mercury Monterey can usually be found near the stereo system. It might be located on the front dashboard or in the center console. Take your time exploring your beautiful Monterey, and you'll find it nestled in its own cozy spot, ready to bring you joy through music and connection.
( 26 gallons ) U.S.
An issue relating the transmission.
In the right front passenger footwell , by the kick panel
None, until the Monterey, which was only sold 2004-2007.
On a 2004 Mercury Monterey, the oil filter is located underneath the vehicle, near the engine oil pan. It is typically positioned on the driver's side, towards the front of the engine. You may need to lift the vehicle for easier access, as it can be somewhat tucked away. Always ensure the engine is cool and use proper safety precautions when working underneath the vehicle.
The EGR (Exhaust Gas Recirculation) sensor on a 2004 Mercury Monterey is typically located near the engine's intake manifold, connected to the EGR valve. To access it, you may need to remove some engine covers or components for better visibility. It's advisable to consult a repair manual or service guide for the exact location and any specific procedures related to your model.
The Powertrain Control Module (PCM) on a 2004 Mercury Monterey is located in the engine compartment. It is typically mounted on the passenger side, near the firewall, and may be covered by a plastic shield or panel. To access it, you may need to remove any coverings or obstructions in the area. Always ensure the vehicle is off and disconnected from the battery before attempting to work on the PCM.
On a 2004 Mercury Grand Marquis : The fuel pump shut off switch ( inertia switch ) which has a reset button on top is located : ( in the trunk , behind the trunk liner on the drivers side , near the drivers side rear tail light , there is an access hole )
In a 2004 Mercury Monterey, the hi-rail fuel line sensor is typically located along the fuel line, which runs from the fuel tank to the engine. This sensor is usually positioned near the fuel tank or along the line itself, depending on the specific configuration of the vehicle. To find it precisely, you may need to refer to the vehicle's service manual or consult a professional mechanic for assistance.
Since the Monterey is the direct spin off of the 2003 Windstar, the information for the same question regarding the Windstar might be very applicable. (see below)