Ignition Key Issues

mark1882 · Post by **mark1882** » Wed Jul 03, 2019 6:26 pm

I have a 53 plate zed and a few months ago started have intermittent problems with doors locking and unlocking with the key fob. Sometimes it would not work for weeks ( had to use the key in the door) sometimes just the passenger door, sometimes both doors.
Having read other people’s experiences and speaking to a car electronics company the consensus of opinion was that the symptoms were likely to be an issue with a faulty GM5 module.
So I had the GM5 unit checked out and it was fine and was told that it was the key that was faulty, it was t working that day, so off to the local BMW dealers to get a new key.
On the day that I went to pick up the new key the old key decided to work ( I think it’s called Sod’s law) but I was so frustrated with intermittent problems with the old key that I had to get the new one.
The new key was coded into the car with a sequence of presses of the key once it had been put in the ignition and all works fine. My old key which was working at the time did not then work. The BMW guy tried to code in the old key but it didn’t work.

So my question is, any ideas as to why the old key will not work, it’s usual to have have 2 keys that work. Any thoughts ?
Thanks
Mark

sharpyboy · Post by **sharpyboy** » Wed Jul 03, 2019 6:51 pm

Could be the rechargeable battery in the old key is on the way out or there was an intermittent electrical connection on the PCB in the key. Did you have 2 keys before you got the new one? Did the 2nd key work ok?, did any of the buttons work on the old key? Open/close/boot pop.

mark1882 · Post by **mark1882** » Wed Jul 03, 2019 10:19 pm

Hi Sharpyboy, thanks for your response, all buttons on the old key worked but only intermittently. Sometimes the old key would not work for weeks and then al” of a sudden start working again either for a day or two or a week or two. It sounds like one of your analysis is correct, a bit frustrating in that it was working when I picked my new key up and since the new has been coded with the car the old key doesn’t work. No big deal just a conundrum..
Mark

buzyg · Post by **buzyg** » Wed Jul 03, 2019 10:24 pm

To code two keys, you have to do them both within a few seconds of each other. There's how to guide somewhere.

buzyg · Post by **buzyg** » Wed Jul 03, 2019 10:33 pm

Here you go found the old thread. Give this a try might help.

viewtopic.php?t=78497

Mr Tidy · Post by **Mr Tidy** » Wed Jul 03, 2019 11:21 pm

From what I understand you can have more than 2 keys coded, so long as they are coded in the right time-frame.

When you got your new one coded BMW should have coded your other one(s) at the same time.

But you can also delete keys from the memory to prevent access by keys "lost" by previous owners.

It sounds like you had a battery issues with your original key - they get an inductive charge when you use the car, but can reportedly be charged by putting them next to an inductive charger like the ones used by Braun (and probably other brands) of electric toothbrush.

I'd be going back to the dealer for a fix - but depending on their response and where you are located there are other options.

I got a flip-style key cut and coded by a "lapsed" forum member in Warrington, but I've also read good things about "bmkeys" in E. London.

Hope you get it sorted.

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