Key for C200 2003 not working properly.

[Lexlie]

Hi!

I know it might not be the best category to post this question, I didn't know where honestly.
I recently acquired a Mercedes Benz C200 2001-2003 and the remote key has a problem which I'm not able to figure out. The key remotely lock the car, can start the engine of the car with no issues but I can't unlock the car from the key. I have to use the physical key and immediately insert the remote into the ignition so the alarm doesn't go off too long.
We've opened the key up and looked for corrosion and loose connections but nothing of those appear. We've measured and tested every part of the key to see if power goes through it or if the contacts are good and everything is fine. When pressing the lock button the key has a small led that lights up showing that the command was sent, but when the unlock button is pressed, the led doesn't light up.

Any suggestions or advice?


Sorry for the long post!

 

[markjay]

Difficult to say if the issue is with the fob, or the car - by the sound of it you don't have a spare key, so can't try a different fob?

If so, then I would start by getting a second key made.... youl'd need it anyway, because it's not a great idea to run a car without a spare key. Once you've done that, you'll know if the issue is with the fob or with the car.

Unfortunately, there's no cheap way of getting a spare key made, expect to pay between £150 and £250. Obviously any MB dealer can do that, but there are also some car locksmiths that can supply a programmed key fob with an energy key cut.

 

[markjay]

Out of interest... is your car a C200 CDI (Diesel), or C200 Kompressor (Petrol)?.

 

[Lexlie]

Out of interest... is your car a C200 CDI (Diesel), or C200 Kompressor (Petrol)?.

C200 CDI (diesel)

From what I understood from the previous owner, the key used to work fine. But one day suddenly the unlock button stopped working. And from the studies I did on the car, the car receives the unlock/lock signal through the same antenna. So I think it has to be the key at fault since everything works fine.
Do you know by any chance if Timpsons do keys like this or any advice than a MB dealership since it will rip my wallet apart?

 

[exvolvoman]

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Don't think Timpsons will be much help, when I needed a replacement for my Volvo they could only cut the key but not do the chip/programming
I got my spare Merc. key from these guys

 

[OneForTheRoad]

Try resetting the fob. But if the red led isn't lighting up the button may well be broken.

 

[Lexlie]

Try resetting the fob. But if the red led isn't lighting up the button may well be broken.

We've tried reseting the fob. No luck at all.

 

[wrdcc01]

Defective button for sure. Check on the solder joints. Try pressing the button pad with you finger nail with the circuit board removed from the case it may be the outer button is no longer applying enough force to make a good contact. Lash up with a bit of folded paper, order a replacement key and keep the old one for a spare.

 

[SailingGypsy]

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Replacement key for your Mercedes. Lost, Spare or broken Mercedes keys we do them all! Call now - Car Key Specialists | Lost MERCEDES Keys and key Fob Experts - Quote: 07563014634 01217722808 - Nationwide service

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Don't think Timpsons will be much help, when I needed a replacement for my Volvo they could only cut the key but not do the chip/programming
I got my spare Merc. key from these guys

I cannot recommend this young man highly enough, my one and only key for my CLK W209 was in a damaged state and very frail as a result.

In just an hour I had a new key & fob married to the car with the original fob refurbished and working perfectly!

Just a shade over £200 for peace of mind.

Thank you Matt. (@ ReplacementMercedeskeys.co.uk)

 

[Martin 1]

I've used these folk before for a second key, but there's almost nothing they can't do re locking / unlocking, and they're nice folk to boot. At the very least give them a ring for a chat. Good luck.