Can a key to lose its program code?

[MarcMB]

A problem in my CLK 320 2001: after 5 years without using the spare electronic key, I tried it and I realize that, while it opens doors and trunk, it does not start the engine. Any idea about what should I do? I am not sure if it worked 5 years ago, I do not remember to have checked it other tahn opening doors.

 

[jberks]

I've heard of the internal battery having issues if not used for a while - certainly 5 years would fall into this category.
Allegedly, it charges through induction from the car, when in the ignition slot. Some people have had success by parking the car in a locked garage for a few hours with the dodgy key in the ignition. This charges up the battery and all all is well again.

 

[MarcMB]

Thanks. I'll try it. It surprises me I can open doors, so key batteries seems ok. Thanks again.

 

[ba9rn]

Thanks. I'll try it. It surprises me I can open doors, so key batteries seems ok. Thanks again.

I believe that the opener and ignition circuits use different batteries. The opener has replacable battery, but the immobiliser+ignition part relies on being inserted. So it is worth a try keeping it inserted for a while (with the car under lock and key!).

 

[television]

I do not think it will do anything with all of the above sugestions, take it to MB and get it re coded.

Malcolm

 

[MarcMB]

Update, for your info:
- I left the key on all night and it didn't work.
- It is true that batteries are not related with the ignition: if you take the back part of the key out (where batteries are) and insert the key, the car starts ok (of course I tried with the key that works, not the one that has the problem). I do not know even if the ignision part has some kind of battery, it might be like an "electronic mirror". It looks as a good design because these 2 tiny batteries shouldn´t be responsible for leaving your car in a gas station 1000 miles from home!.

I´ll go to a MB dealer and I'll keep you informed. Thanks folks to all of you.

 

[bitonw]

With my old car (Lexus) it happened a couple times that the ECU 'forgot' the key. The only way to get it working again is to reprogram the key with the ECU as Malcolm told before. So go to your dealer with your keys and let them reprogram it.

 

[MarcMB]

End of movie: dealer confirmed that key has 2 independent circuits, the ignition circuit can lose its program, but in my case it was damaged (probably because it was never used in 5 years). So I ordered a new key, which is not cheap as you know. Lesson learned: use periodically both keys.

 

[television]

Outside repair firm are now getting the key coding equipment, not for all cars as yet,the first one being released is the Sprinter, others will follow, I will keep you posted.

Malcolm