Key's Battery.
 

i have a keyless go in my '04 e320.

since i bought it in 04, i already get the dealer to replace the battery once.

now, i cant open or lock my door properly. i believe this suppose to be the problem with the key's battery.

so my questions are:

1. should i get the dealer to replace the battery for me again? i know that those battery cost much more in the dealer compared to those groceries store. if i can get it outside the dealer, anyone know about specific number for the battery? i've once tried to buy the battery outside the dealer but it does not want to work.

2. does having a keyless go makes your key's battery drains faster?

thank you.

never mind, I thought you were talking about car battery.
If fob battery, it is CR2025. You can get it at camera shop, office depot, Circuitcity...almost everywhere.

Radio Shack. Cheap enough. Really easy to install too. It will cost you far, far less than at the dealer. You'll need two batteries.

thanks for the reply guys,

i forget to check the thread today and i already went to the dealer to get it replaced. the dealer charge me for around $17 for it and i know for sure that it's a damn rip off.

regarding about car having keyless go drains key's battery faster, i still cant get an answer for this. anyone can explain this to me?

thank you.

$4.99 ea. at radio Shack... and you need 2
http://www.radioshack.com/product/in...104&cp=2032056

Yes, Keyless go will drain the batteries faster than normal. When the remote key is inserted into the EIS, the switch handles the power supply. When you use Keyless go the antennas are constantly transmitting data to locate the key inside the vehicle. Try this... start the car with keyless go, then remove the keys batteries. The car will eventually shut the engine off when you come to a stop because it will no longer recognize the key being in the vehicle. That is also why you get the message "remove key" when you shut off the car using keyless go. Just a reminder to take it out with you.

Not really a necessary reminder because you can't lock the car with a keyless go smartkey anywhere inside the car.