BSI central locking again

[ffrenchie]

Rather than resurrect an old thread, after about 18 months of no central locking I spotted a BSI on eBay and have decided to have another look. I read that the top board in the BSI is nothing to do with the part which is programmed to the key so I am going to try putting the top board of the eBay BSI onto the bottom of the one out of my car. Much huffing and puffing later and several profanities I finally got the boards separated using of all things a thin wood chisel as none of the proper electrical tools would touch it so now I have a BSI in bits and in a bit I am going to go out and pull the BSI from the car. Hope this works. 

[mikeB]

Rather than resurrect an old thread, after about 18 months of no central locking I spotted a BSI on eBay and have decided to have another look. I read that the top board in the BSI is nothing to do with the part which is programmed to the key so I am going to try putting the top board of the eBay BSI onto the bottom of the one out of my car. Much huffing and puffing later and several profanities I finally got the boards separated using of all things a thin wood chisel as none of the proper electrical tools would touch it so now I have a BSI in bits and in a bit I am going to go out and pull the BSI from the car. Hope this works. 

I used a wooden school ruler to separate the boards. Very much like what you used. And yes, you are correct. One board contains all the programmed parts, linked to the vehicle, and the other is simply a collection of servos (current amplifiers). 
I found the removal of the 3 (I think) multiplugs to be the most difficult process as access is very tight.
When reassembling make sure you use an electrical spray (switch cleaning lubricant) on the 2 sets of pins, and the sockets, before you put the 2 boards together. The signals from the control board (the one you will retain) are small so you need good contact with the servo board. I used a Briggs product but Electrolube or Servisol Super 10 is more easily available. Do NOT use WD40. And wipe off any overspray on other parts of the boards. You need to squeeze the 2 boards together SLOWLY, a bit at a time.
I had exactly the same problem as you and replacing the servo board was the answer. Good luck - and don't throw the old board away - it might just be those pins that are the problem.

[Sol]

Very interesting, let us know if it works. Not for the feint hearted but if the top board is only I/O then it could well work.

[ffrenchie]

I used a wooden school ruler to separate the boards. Very much like what you used. And yes, you are correct. One board contains all the programmed parts, linked to the vehicle, and the other is simply a collection of servos (current amplifiers). 
I found the removal of the 3 (I think) multiplugs to be the most difficult process as access is very tight.
When reassembling make sure you use an electrical spray (switch cleaning lubricant) on the 2 sets of pins, and the sockets, before you put the 2 boards together. The signals from the control board (the one you will retain) are small so you need good contact with the servo board. I used a Briggs product but Electrolube or Servisol Super 10 is more easily available. Do NOT use WD40. And wipe off any overspray on other parts of the boards. You need to squeeze the 2 boards together SLOWLY, a bit at a time.
I had exactly the same problem as you and replacing the servo board was the answer. Good luck - and don't throw the old board away - it might just be those pins that are the problem.

I've had the old one apart before but chickened out when the boards would not separate. I have contact cleaner which I use for everything electrical so that's what it will get (whether it likes it or not   ) I read that the pins on the relays for the central locking should give a reading of about 80 ohms and these read 84 so I am optimistic. Just having dinner then it's out into the cold to take it out and take it apart. Laters

[ffrenchie]

All back together and working as it should, I even installed some new BSI clips that I've had in the glove box for about a year. I'll leave it alone now before I wear it out
I'll put the spare one back together and keep it for spares, or forget where it is.

[mikeB]

All back together and working as it should, I even installed some new BSI clips that I've had in the glove box for about a year. I'll leave it alone now before I wear it out
I'll put the spare one back together and keep it for spares, or forget where it is.

Nice feeling when it works again. I still suspect your servo board was OK, but the connecting pins caused the problem. Anyway, it's working again so enjoy!

[ffrenchie]

Nice feeling when it works again. I still suspect your servo board was OK, but the connecting pins caused the problem. Anyway, it's working again so enjoy!

I tested the pins on the relays and on the old board there was no reading on one of them so the relay was shot. The unlock relay was still working and read 88 ohms. The two on the replacement both read over 80 ohms and both work fine so not the connectors.

[mikeB]

Nice feeling when it works again. I still suspect your servo board was OK, but the connecting pins caused the problem. Anyway, it's working again so enjoy!

I tested the pins on the relays and on the old board there was no reading on one of them so the relay was shot. The unlock relay was still working and read 88 ohms. The two on the replacement both read over 80 ohms and both work fine so not the connectors.

Your solution was definitely the correct one then. I did try to source new relays for mine, without success, and then, like you, found a replacement BSI and swapped the board. Those lock relays must take a lot of current! Good work!

[ffrenchie]

Here's a few pictures showing the relays that control the central locking. The BSI came with all the connectors so it was handy for practising undoing them, they can be awkward. The relays are shown on the top board and underneath I marked the pins which activate the relay coil, they should read between 80 and 100 ohms. I have read of people soldering tails to the connectors and fitting off the shelf relays. The good relay shows 85.9 ohms and the bad relay gives no reading which shows as a 1 on my cheap Screwfix tester. I think the hardest part was getting the two boards apart and fitting them back together which took a lot of pressing to get the pins fully home and the next hard part was getting it back into the car connected up. The connectors are all colour coded with French names, noir, vert, gris etc. It's been a job worth doing and it cost me £32, a lot less than the £145 plus postage on various sites on the net.
                   

[mikeB]

Here's a few pictures showing the relays that control the central locking. The BSI came with all the connectors so it was handy for practising undoing them, they can be awkward. The relays are shown on the top board and underneath I marked the pins which activate the relay coil, they should read between 80 and 100 ohms. I have read of people soldering tails to the connectors and fitting off the shelf relays. The good relay shows 85.9 ohms and the bad relay gives no reading which shows as a 1 on my cheap Screwfix tester. I think the hardest part was getting the two boards apart and fitting them back together which took a lot of pressing to get the pins fully home and the next hard part was getting it back into the car connected up. The connectors are all colour coded with French names, noir, vert, gris etc. It's been a job worth doing and it cost me £32, a lot less than the £145 plus postage on various sites on the net.

Brilliant photos. Your work on this repair prompted me to check the relays on the board I swapped out some time ago when the central locking stopped working. The coil of the upper relay in your picture No 2 was fine, as was the the lower one. BUT, the lower relay was a different make - a TYCO V23076. Your photo also shows a further YH119 - of the 1Z (45 amp) variety in the extreme top left corner. The coil of the relay in this position on my board I now find is  open circuit, and therefore the likely reason for the central locking fault. It seems the layout of our respective boards is different. I mention this in case anyone uses this thread in future to solve a central locking problem. Anyone doing that may be interested to know that a source of the YH119 1Z relay is currently here

https://uk.farnell.com/te-connectivity/v...dp/1024021

It's a different manufacturer but the spec is the same. They currently (Jan 2021) have over 5000 in stock and the cost is under £5 plus delivery. Removing the relay needs at least a 100 watt soldering iron and a good quality solder sucker. Well done again. Another successful repair for the archives.