[Tica]

2000 C280 Sport. Have owned it for four years. Yesterday, when I came back from buying gas, the car would not recognize the remote and start. FOB batteries are newish. Car has been sluggish to unlock in past two months but otherwise starts fine. Finally, after repeated insertions, the FOB was recognized and I drove it home. Today, it will not recognize either FOB either to start the car or lock it and I cannot turn the alarm off.

I guess I will manually open the truck and pull the cable. Can the system be reset? I also am beginning to suspect the battery, which is four + years old.

 

[acousticplayerjb]

Yep, get the battery tested. I would suggest replacing a battery that old anyway since it's only a matter of time before it fails (especially since winter is approaching).

If you leave the battery unhooked for a night, I think the ECU will reset. But honestly, I don't know a whole lot about how the keys work. Have you just left the key in the ignition for a few minutes? Perhaps that will allow the system to recognize it, but again I'm really not sure. I remember that when I had problems with my keys, the dealer programmed a set of the newer keys for me. My car originally had the elongated smart keys, and now it has the shorter ones. If a dealer does it for you, it's going to cost you some money

 

[Tica]

I replaced the battery but the problem persists. The alarm will not disengage and the key is not recognized. So I bit the bullet and gave up trying the preserve the radio codes and disconnected the terminal. Even with both terminals disconnected. I can hear a faint warble coming from the alarm. I guess there is a capacitor or reserve battery which holds a small charge. The tow truck is the next option.

 

[davo]

the only other way is to get it on the star system and get both disabled, it may sort the problem out for u

 

[Tica]

Solved. Battery was weak. FOB also went dead. This FOB was 10 years old and I guess used its maximum number of starts, whatever that is. Using spare FOB and have ordered a new one - $224.95. Plus $88 for a new group 49 battery at Sam's. The group 93 battery (OEM) is about $98 at Autozone or Advance. Both come with the vents, fittings and conversion tubing. Autozone doesn't show the battery for a Mercedes, but lists it for Jaguars.

 

[FAR888]

Solved. Battery was weak. FOB also went dead. This FOB was 10 years old and I guess used its maximum number of starts, whatever that is. Using spare FOB and have ordered a new one - $224.95. Plus $88 for a new group 49 battery at Sam's. The group 93 battery (OEM) is about $98 at Autozone or Advance. Both come with the vents, fittings and conversion tubing. Autozone doesn't show the battery for a Mercedes, but lists it for Jaguars.

Hello Tica,

I'm pleased you eventually solved the problem and thanks for posting the solution.

In relation to the purchase of a replacement key, what documentation is required to get the replacement and crucially, does the car have to be present for the key to be programmed?

My brother needs a replacement key for his 1999 C230 Kompressor but the car is over here in West Africa.