repairing broken W202 Key fob.

[anyweb]

so thanks to andy and the forum

heh, my name is Niall but thanks for the thanks anyway

 

[jamie-ann]

On my fob the battery connector is broken
Its actuallh the small pointy bit thats meant to hold the battery down. Where can buy one please

 

[anyweb]

why not just solder on some new metal or the metal that broke off

 

[Fizzo2]

It won’t do any harm to check the fob when you are at it.

Dec

Thanks for this.

For some reason my mobile phone (iPhone 4s) didn't show up the infra red signal so I thought my repair had not worked. But later I tried it using my digital camera (Canon SX220) and it showed up bright and true. So beware.

 

[Fizzo2]

thanks malcolm, it sure was a relief when the key worked after the soldering job !

cheers
anyweb

Thanks Anyweb.

I notice these great instructions are from 2008 but I have still benefited from them in 2016! Managed to solder a new tactile switch on to my spare key and it works again. Brilliant - saved over £200 from the dealer.

I had to buy a minimum of ten tactile switches and only used one - so if anyone would like to have one I am happy to send it.

 

[AlongfortheRide]

I have a c280 1998 mercedes. I recently tried replacing my batteries in my key fob. Since doing that my car won't turn on and the lock/unlock door function is not working either. I am thinking that maybe the circuit chip is damaged but am unsure by my untrained eye. Anybody have experience with the engine not starting due to a key fob failure? I have the single button switchblade key. There is no flashing light when I try to push the button and look at it through a camera phone. I tried with new batteries yet there still is no light available. But my biggest concern is the engine won't start.


I have read through almost the entire thread am an unsure of what next step to take. Any ideas?

 

[television]

I have a c280 1998 mercedes. I recently tried replacing my batteries in my key fob. Since doing that my car won't turn on and the lock/unlock door function is not working either. I am thinking that maybe the circuit chip is damaged but am unsure by my untrained eye. Anybody have experience with the engine not starting due to a key fob failure? I have the single button switchblade key. There is no flashing light when I try to push the button and look at it through a camera phone. I tried with new batteries yet there still is no light available. But my biggest concern is the engine won't start.


I have read through almost the entire thread am an unsure of what next step to take. Any ideas?

You are welcome to post it to me, it might be fixable.

 

[AlongfortheRide]

I just took the key fob to my local key shop and they were somewhat helpful.

They said that the transponder was missing and without this transponder (RF?) the engine will not start as a security measure. They described it to me and I believe I have it. I think it flew out when I was changing my batteries. They say its a black rectangular block the size of a rice grain. Does this sound familiar at all? I believe I found it but I am not sure where it is supposed to go in the context of my key remote. Does anybody know this?

They also were able to get my infrared flash working. It seems to work with only 1 battery. Not sure why that is but I think the chip where it connects too is not in good shape?

 

[television]

That coil cannot be put back as its broken, its hard to say for the rest, best to contact Mark for a new key.

 

[AlongfortheRide]

Just an update. The car now starts and works thankfully! When I took the key apart, the RFID chip (transponder) needed to start the car flew out of my key. I found that part and inserted it back in my remote key and the car started. Without that RFID chip, the car won't start as a security measure so keep that thing secure and be careful with it because I don't think there is any way to get a new one if it is damaged or lost. You probably have to buy a new key. I am not sure about that last sentence, I actually would be interested to know if you are able to get a new RFID chip if needed). Anyway, glad things worked out.

I wasn't aware that the RFID chip was not part of the circuit board. One of the first things people should do if their car won't start due to key issue is make sure the RFID chip is still inside. It is not hard for it to fly out especially on older keys.

 

[television]

Just an update. The car now starts and works thankfully! When I took the key apart, the RFID chip (transponder) needed to start the car flew out of my key. I found that part and inserted it back in my remote key and the car started. Without that RFID chip, the car won't start as a security measure so keep that thing secure and be careful with it because I don't think there is any way to get a new one if it is damaged or lost. You probably have to buy a new key. I am not sure about that last sentence, I actually would be interested to know if you are able to get a new RFID chip if needed). Anyway, glad things worked out.

I wasn't aware that the RFID chip was not part of the circuit board. One of the first things people should do if their car won't start due to key issue is make sure the RFID chip is still inside. It is not hard for it to fly out especially on older keys.

OK so yours is the flip out key That would explain it all.

 

[Benge]

I have been following this issue to where I have tried to repaired two remotes. When I opened them up it did not seem like I had a solder problem but I went ahead and put a dab of solder on each leg. This repair did not repair The initial problem. Have you had any further replies from any other User that could send me to the next step. There was a mention of the switch being bad itself. If i tested the switch I would assume that they are "NO" normally open and I would get a reading when the button is pressed down? BTW this was an excellent write up. Do I have any other options?
Benge
Orlando, Fl