405 key repair

ciderheadz1 · Post by **ciderheadz1** » 11 Oct 2008, 00:43

After weeks of sourcing info on the 405 key not working anymore problem It is up and running again.There seems to be a lot of misinformation regarding the 405 key (or at least the early ones) with plenty of ebayers trying to sell you a fob or info to make your key work again.The 306 method did not work on mine but maybe on a later 405 it would.The 306 key reprogramming method is well documented in this forum.
From what I discovered the receiver (plip)in the roof panel has a number on it which corresponds to the same number in your key fob (remote) and these are a matched pair so no other remote will work or reprogramme so don't be tempted by some unscrupulous sellers promises on ebay that buying his info or remote will have it all working again.As I found out the chances of finding a matched plip and remote in a breakers etc seems to be zero and even if you did i am not sure wether an ecu would be required also?
I got mine working again by taking it to a mate who happens to be very good with electronics and soldering small components.I gave him my non working key, a known good key for testing purposes and 3 old keys in case he had to change parts, I also told him how to check if the remote was transmitting a signal by pressing the button and looking through a digital camera or camera phone screen (doing this you will see it light up which you can not see with the naked eye) I then left him to it .I assume there must be some sort of rom on the remote (read only memory) and was fully expecting him to use my rom in another remote pcb to make it work again.But I struck lucky all he had to do was resolder the components on the board and all was well and I was one happy chappy.
Hopefully someone will find this info helpful and wont have to endure weeks of brain strain as I had to whilst trying to overcome the problem without having to spend a fortune on an old car.

citroen7 · Post by **citroen7** » 11 Oct 2008, 10:05

the early ones must be the same as the bx then ,the other thing you can do is take the code number on the reciever to your main stealer and he will order you a new plip from the factory the last one i got was about £30
but that was a few years ago..

TBONE · Post by **TBONE** » 12 Oct 2008, 22:40

once the plip/remote has been programmed it cant be altered so not worth buying from ebay unless your looking for a cover

ciderheadz1 · Post by **ciderheadz1** » 13 Oct 2008, 22:29

My mate whos into small components reckons it would be easy to remove the rom from mine and resolder it to a working pcb.If mine plays up again that is what he is going to do.Could be interesting.If it happens I will let you know if it works.