david11946

Hello all,

I am as new to Mercedes ownership as much as I am new to this website. I have a 2003 C240 that I have come to own pretty much by accident. I co-signed for it for a family member that eventually defaulted on the loan. I parked it in my garage and got on with my pretty busy life and after about a month of not starting the car, the battery died. I soon realized that the space aged key fob was some sort of transponder and not an actual metal key. How do I open the doors to start with the battery replacement? Is this car as 'do it yourself' proof as it seems? Any and all assistance with this problem would be deeply appreciated. I'd hate to need to call a Mercedes "stealership" to get me out of this issue.

Thanks to all

David

VVF

Does this help?
https://www.youtube.com/watch?v=yOZmx7dSyxQ#t=24

david11946

Thanks for that info.
That's another item that is good to know. However, it's not the key fob that suffers from a dead battery. It is the battery for the car itself and all the doors are locked. Any information on how to get the hood opened to change or jump the battery?

Also, the mechanical key that he removed from the key fob fits into what? I didn't see any key holes on the door handles of the car? Thanks for your help.

efzauner

the key on the fob does fit into the key hole in the door handle! It should be quite obvious.
Then of course you should investigate why the battery is dead. Try recharging the battery then starting. You will have to test weather its the alternator/charging system or the battery that is the culprit. The battery is a normal car lead acid. Put in whatever fits. You don't need to go OEM.

cm60k

I think this mechanical key for Glove storage box, isn't..??



ZAYED,,

Moviela

Sorry, it is not a "normal" battery. It is has a huge capacity, and not easily found in the after market. It is bad advice to use "whatever fits." An undersized battery will cause undesired operation of electrical systems on the car. Don't use less than a 100 Ah battery in the car. (Mercedes has recently migrated to AGM batteries that cost twice as much ($300) and are rated 95 Ah. They are acceptable.)

A car left sitting for 30 days with an older battery could discharge completely. A test with proper workshop testers can tell if the battery is still useful after being recharged.

You can open the driver's door with the metal key to open the hood. It is strictly mechanical. Follow the strict instructions for jump starting, or you might cause damage to the rear SAM and an additional thousand to replace it.

You might call Mercedes Roadside. Their service is free, and they will resync those items necessary after a flat battery is jumped. See the sticky for details to do it yourself.

david11946

Thank you all for the info. I've been so busy with work and family that I had to just clear my schedule so that I can fully inspect and explore this car as I've never previously owned a Mercedes. I sprung for a new battery and judging from the noise coming from under the car, I'll possibly be buying a new cat converter also. The car has definitely got a bit of spunk for a 2.6L.

Thanks again for the help...