Keyless door pads

You cannot reset the keyless entry on any ford product. You can add additional keyless entry 5 digit codes but only if you know the original code. A dealer can retrieve the original code as along as you can prove you own the vehicle. some charge for this service.

Mercury Mountaineer 2002 2005 Factory Service SHop repair manual Download

for the easy solution download the pdf file

one way to find out is to sit in your vehicle on the drivers side. lock all the doors, stick the key in the ignition and turn it to the on position without starting it then to the off position 9 timesrepeaditly if on the 8th or 9th time the locks unlock then lock or vice versa then the vehicle did come equipt from the dealer with keyless entry remotes. hope ive been helpful

Well the only way to do that is to look on the Keyless entry module in the car, or retrieve it with a computer which again you would need to get in the car. Your best bet is to call a lock smith and have him open it. We have a company here called Pop A Lock that will come out for i think $45

You will have to go to the dealer with tittle,and proof
of ownership and VIN# to get the factory code.

You should have 2 keys and a valet key, then program them,
then change the Keyless Door Code

TRY THIS REPROGRAMMING PROCEDURE. SWITCH THE IGNITION OFF TO ON 8 TIMES WITHIN 10 SECONDS. DOORS SHOULD LOCK THEN UNLOCK. PRESS ANY BUTTON ON THE FIRST REMOTE TRANSMITTER. DOORS SHOULD LOCK THEN UNLOCK. IF YOU HAVE ANOTHER CAR REMOTE REPROGRAM IT THE SAME WAY. WHEN DONE SWITCH IGNITION SWITCH OFF.

In the 2002 Mercury Mountaineer, especially with the 3rd row seat, remove the trim panels at the rear of the back door and at the tailgate on the passenger side. You will see two panels where the wall seat belt is located, remove the top panel first and then pull the lower panel out.Then pull the lower trim panel forward CAREFULLY. Towards the front (near the door opening) you will see a small black box (says Security Unit) On it in fairly small print will be the 5 digit code.
[ONE set of FIVE numbers and that is your CODE number.]

Stop by a dealer. Give them your Vin# and they should give you the factory code.
Then stroll into the service bay, like you own the place,get a tech off on the side, to write down, how you progam your own code,into the keyless entry pad

Driver door module is where to look also a broken or corroded wire and if you use your key to punch in the door code then the key pad has a hole in it or it just went bad it's not the remote control also check the master door lock switch for corrosion at the pins and the plugs same with the driver door module

The keyless entry module is located in the rear of the vehicle on the driver's side. You will need to partially remove the left rear panel in the cargo area. You will then see the keyless entry module bolted behind a metal reinforcement bar. There is a sticker on the module that has the 5 digit entry code.