Key remote blues

[grober]

2 years ago I bought two new remote keys from my local MB dealer having had problems with the original one I was using-it stopped working at 11.45 pm on a cold december night stranding me 100miles from home. At first the new keys didnt work but the parts guy took them away for 5 minutes to the workshop and then returned them fully operational. This week one of the two "new " keys failed again. tried new batteries, reactivating in the ignition etc to no avail. Went back to the dealer complete with invoice. The parts guys were helpful but said it was a warranty type claim. thats when things went a bit pear shaped. I was told that in order for the dealer to process my claim I would have to book my car into the workshop. A technician would plug my car into the diagnostic system to generate a fault code. Only on production of this fault code plus a technicians report would mercedes be prepared to replace the key.
I said I was prepared to leave the defective key with them but couldnt see why they needed my car a 1996 e 220 coupe w 124 series for a morning to determine my key was broken. If they could active the key without my car surely they could test it also. NO NO they had to have the car. Is this correct or were they just being difficult. I didnt think my old car had the facility to interrogate the central locking system thro the diagnostic plug anyway.

ANYWAY
for those who wondered about whats inside these keys I performed a bit of surgery ( CRUDE) on my original key. (see the attached picture). using a hacksaw and stanley knife I removed a rectagular section containing the operating button. Inside I found a small button switch attached to a circuit board by 4 legs.
one of these had broken. ( I have outlined this in red in the picture.) once i soldered this back in place the remote worked again. Its obviously a weak spot which is stressed every time the button is pressed. I have effected a CRUDE repair using araldite but if you want to attempt the same repair use the larger rectangle cutout I outlined in red. If you are careful you should be able to glue it all back together afterwards.
If anyone can shed some light on this "fault code business" I would be grateful.

 

[grober]

remote locking test.

Still trying to figure out my remote problem. Came across this test on another forum. To test whether the key is sending an infra red signal operate it while looking thro the Display screen of a Digital Camera. In addition to the red Led illuminating as normal you should see an IR PULSE of white light. See blurred photo attached. Dont think this will damage the camera Still doesnt explain why my key doesnt work tho.

 

[grober]

Key Recoded yeah!!

Having tested my key was still operational with the digital camera trick finally managed to recode my key by a combination of 1. key in PASSENGER DOOR LOCK (not the ignition as stated in the manual ) 2. unlock manually then 3.press the remote twice for 5-10 secs then 4. lock manually again.5. Leave key in lock for about 20 seconds then remove. Hey Presto it works. trouble is I tried so many permutations of the above routine that I,m not totally sure if thats exactly what I did. the key to success seemed to be
1. using the passenger door lock not the ignition.
2.doing everything slowly to allow the system to learn.
Still would like to see someone post the "definitive method" for recoding IR remotes for cars of my vintage.

 

[Dieselman]

Well done on fixing the coding fault.

The dealer isn't being difficult, they cannot make a warranty claim without having supporting diagnostic evidence.

 

[dtorbett]

Can you recode any key like this

Does this recoding work for any key?
I ask because I bought my 2001 c class 2 weeks ago and have discovered that 2 of the 3 keys do not work for the car. I suspect I have 2 keys for another car. The dealer has confirmed he has all the keys for his cars so he can only assume the auction where he bought it have mixed things up. He is progressing the issue with them for me, but I thought if this recoding works, I might give this a try!
Thanks
DT

 

[grober]

Dont let it drift!

Almost certainly NOT I'm afraid. Only applies to simple IR keys of that early 90's vintage. I understand that later keys are far more complex with IR/radio links and "rolling" codes that change every time you use the key Other forum users have posted on your age of key so if you do a search you might get some more info. Make sure that the issue with your dealer doesnt" drift" These later security keys/systems dont come cheap and if you are entitled to 3 keys then thats what you should get.

 

[dtorbett]

Anti-Drift bat at the ready

Thanks for the tip. I didn't think this would work but it was worth a try. I will continue the fight with the garage and hopefully I'll get a result. Someone else somewhere is 2 keys short so I hope they work it out soon. If I took the keys I have to a stealer, would they be able to work out which car they came from (which exact car). I realise they probably cannot tell me directly, but maybe they can tell the garage. Either way I'll be making sure that I get my 3 keys one way or another - foc!
Thanks
DT

 

[grober]

Previous Owner

From what you are saying I am deducing that your "DEALER" is not a MB agent but trader who bought the car at auction. 2 things come to mind.
1. can you contact the previous owner from the log book to check if they have the original keys?
2. there are potentially 2 keys out there which IN THE WRONG HANDS will unlock your car and drive it away
If your dealer can't supply the original missing keys try to get the money for a new set of keys and locks from him.

 

[Ashley]

I went to open my car before and guess what it wouldn’t open remembering this tread I was caking myself the car was not parked somewhere I would leave a car in dark. Happily it was just the batteries