Key fob stopped working the door locks. I changed

Be sure to use the correct battery, properly in place, clean the key contacts , See owner's manual for additional information.
There are specialized locksmiths for car keys

Try a fresh battery in the key fob control.

If your key fob has just stopped working try this:

1. Unlock your vehicle with the key in the drivers door lock, do not open the door.
2. Press the right hand button lock button (the button with the padlock symbol or the dimpled button) on the key fob 4 to 8 times.

If the above fails try this:

1. Open the key fob
2. Remove the battery
3. Press any button 10 ten times, and the same with the other button
4. Refit the battery or a new battery
5. Unlock the vehicle with the key in the drivers door lock, do not open the door
6. Press the right hand button lock button (the button with the padlock symbol or the dimpled button) on the key fob 4 to 8 times

HAVE YOU TRIED CHANGING BATTERY IN FOB

IT WORKED!!!! The manual on my 99 ML430 to "Resynching Remote Key" was just written weird.

It says "Turn the key in the ignition to 2nd position then back to 0. Press and hold the lock key for 15 seconds... now press the unlock key 5 times"... which I held down the lock button for 15 seconds, released it, then pressed the unlock key 5 times. NOTHING!

The newer manuals say press and hold the lock key and press the unlock key 5 times (with the lock key still held down).

So... it worked. Hope this helps!

Insert key into door barrel or ignition lock and turn key, whilst doing this press the unlock/lock button, the led on the dash should flash to indicate this has initialised the key to the car, then remove key and test operation of remote. If this fails then a new remote plus coding to the car by your dealership is needed

I'm more familiar with Range Rovers and Saab's when it comes to key fobs but if you changed the battery you have to re-program the key fob. If you do not have an owner's manual that can take you through the steps you might want to try: push and hold the lock button on the key fob, put it in the driver's side door and turn to lock. With the button still depressed turn back to open, remove the key and release the button. If this doesn't work check any and all fuses associated with your system and last but not least you could take it to a dealer. Good luck!

If you look very closely at the lid for the transponder the positive and negative symbols are shown.On the batteries themselves you will see the markings. Once you get them installed hold your lock or unlock button and make sure you infrared light is illuminating in the clear lens There may even be an l.e.d that illuminates. The problem is probably your synchronization. Put key in the door tumbler and turn it. then remove key and attempt to use central locking. You may find you have to put it in the ignition and turn to position 2. The resynch. procedure should be in your owners manual. Hopefully the vehicle starts and you didn't knock the microchip out of the key as well. Hopefully I have been helpful

get in your car close door hit the unlock button then put key in the ignition cycle the key from off to on (STOP BEFORE START POSITION) cycle key off to on 7 times after the 7th trime the doors should lock the unlock automatically that means u are in trainning mode hit the unlock button on key fob. the key fob should now work if it doesn't then try changing batt