E36 key fob issue

[jimwilli]

I have an E36 with 2 original key fobs. Both used to work as of the beginning of the week however one is used as a spare and one is used all the time.

I unlocked the car with the spare fob this week, then locked it again. Ever since then the main fob hasn't worked with the car. I have tried the battery but it makes no difference. The red led at the top of the fob comes on. Is it possible for the car to lose sync with the original fob? Any tips to fix?

Cheers

[guards red]

Hi, you need to know what alarm system you have as it's important to the solution needed.

It should be fixable so don't despair!

This should help:

https://www.bimmerforums.co.uk/threads/e36-alarm-i...

[jimwilli]

Cheers

I came across this from that forum which seems to be a solution - https://zroadster.org/articles/3g-ews-remote-fob-p...

It's a bit perplexing as to why using the spare made the car forget the 'main' fob. It's also disappointing that the fix looks so fiddly. I think it will be a job for the garage when it goes in, I could end up breaking something following those instructions.

[Sticks.]

I don't know if this will fix it, but it's simple and free. It did on my E46 when one randomly stopped working.

https://programyourkeys.com/program-your-car-keys/...

[guards red]

jimwilli said:

Cheers

I came across this from that forum which seems to be a solution - https://zroadster.org/articles/3g-ews-remote-fob-p...

It's a bit perplexing as to why using the spare made the car forget the 'main' fob. It's also disappointing that the fix looks so fiddly. I think it will be a job for the garage when it goes in, I could end up breaking something following those instructions.

I think it might cause a mismatch in the rolling code system. The fob talks to the alarm and the code changes each time. Maybe this kind of use confuses the system.

[Sticks.]

guards red said:

I think it might cause a mismatch in the rolling code system. The fob talks to the alarm and the code changes each time. Maybe this kind of use confuses the system.

One of the keys on my Z4 has that issue DME/EWS I think. The bad key opens the doors remotely, turns on the ignition but won't crank.

[jimwilli]

Update. The passenger door lock has occasionally been sticking. Today when we got somewhere the other half pushed it down which locked all the doors then we shut them. Coming back to the car the fob didnt open it straight away i presume to do with manually locking. I thought i might have to use the key but after a few pushes the fob (spare one which we are using since main failed) Unlocked it. When we got home i thought ill try the other fob now that the system seemed to have a hiccup. Hey presto both now work. Unsure if the other fob would have now worked anyway after a few days or if the wobbly did indeed reset something but thought id post the result. Never know could be an easy fix for someone. Thanks for all help and links

[Sticks.]

Glad it's working again. Electrics issues, particularly ones which don't make sense, can be a sign of a failing battery.