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[johnnydog]

Sorry to resurrect this......both my keys worked for a short while after my last post, but then they both packed up within a matter of a week or so - wouldn't unlock / lock the car or operate the boot release. The car was off the road for most of last year, and whenever I've used it since, I've locked it through the drivers door, which has done my nut in.....

Laterly, the interior light has been staying on when the doors have been shut (although the puddle lights have timed out), which kicked started me into sorting out the gremlins again.
cam.in.head has given me some helpful pointers regarding the interior light issue (cheers Chris), but I decided to try and sort the c/locking issue whilst in the drivers kick panel area.

I decided to remove the anti theft / central locking ecu from an identical breaker (age, engine and spec) having first checked that it operated the doors etc from the key for that car. Amazed that I have been pilfering it for parts for probably 12 years, with a new fob battery, it locked and unlocked all doors etc perfectly. I then removed the ATWS ECU and fitted it to the problem car, and bingo, it locked / unlocked all doors with the fob (had to replace a lazy passenger door c/l motor, but the least of my worries) and it also popped the boot perfectly.
I intend to get the original keys checked again by a different place, along with the original ECU.
Am I right in assuming that I can instead use this apparently good ATWS ECU in the problem car, with the 3 button part of the key fobs, with the horseshoe / blade and transponder chip from the problem car as one unit, as I understand from the previous posts, the button part of the fob just operates the ATWS and the c/locking etc, and the transponder chip speaks the engine ECU for engine starting, just to keep one key to operate everything?

Sorry to drag this up again...

[cam.in.head]

yes the key physically turns the locks it is cut for, the little removeable chip operates the immobiliser ring and the ( detacheable) section with the buttons works with the alarm/cl ecu it is programmed to .  all 3 completely isolated systems of the car .

[johnnydog]

Thanks very much again Chris!

[TheBoy]

If you use the donor ATWS with the donor fobs, but use the original key blade and transponder from your car, you ill have no issues*


*unless you need new fobs programmed to the car, as they will need the PIN security code from the donor car.  Programming new transponders will still use the PIN security code from your car.

[Doctor Gollum]

Car pass from donor car will take care of that, but belts and braces would be V5, VIN and Registration number as well.

If the car is still in your possession that will make it alot easier to obtain the car pass.

[johnnydog]

That's OK then thanks. Got the car passes for both cars, so hopefully that side of things sorted if needed.
Is there a remote (no pun intended!) possibility that the ECU is the problem - just can't see that both keys fobs would loose communication with it, on such a frequent basis..... It did have quite a bit of water getting in around that area down the A pillar under the trim from the leak on the sunroof drain a couple of years ago. I've opened the ECU up, and there's no obvious signs of an issue.
Hopefully getting the keys checked this afternoon

[cam.in.head]

so if im reading this correctly ....... you have now fitted a cl ecu from a donor car and all the central locking now works fine ? ( using your original 'keys' and the new donor push button sections .
if this is correct then obviously it sounds like there was a fault in the original unit . so realy that means " job done / cl fixed . presume you just want the original fixed as a spare ?

[TheBoy]

That's OK then thanks. Got the car passes for both cars, so hopefully that side of things sorted if needed.
Is there a remote (no pun intended!) possibility that the ECU is the problem - just can't see that both keys fobs would loose communication with it, on such a frequent basis..... It did have quite a bit of water getting in around that area down the A pillar under the trim from the leak on the sunroof drain a couple of years ago. I've opened the ECU up, and there's no obvious signs of an issue.
Hopefully getting the keys checked this afternoon

I'd say 50:50 TBH.  The FL keys fail with frightening regularity. They are shite!

I've seen the ATWS fail, usually due to water ingress, but nowhere near as common.  The fact both keys failed simultaneously is the only think that makes this a possibility TBH.

[TheBoy]

Oh, and the amount of varnish applied to the PCB on the ATWS makes repair probably not worth it.  Esp as you have a working donor, and the codes from that donor

[johnnydog]

Well, I had both keys from the problem car checked in front of my own eyes - both keys transmitted a signal from all 3 buttons.
Which led me to think that the original ECU may have actually been affected by water ingress (possibly?). Perhaps a gluten for punishment, but I decided to throughly but gently clean all the contacts for the connector block on the 'problem' ecu. Refitted it, and hey presto, the c/locking worked with both original keys as did the boot release. Tried it umpteen times and all was well. Even the interior light behaved itself and went out as it should
Cracked it I thought. Although the c/l was working ok, unfortunately, the interior light issue came back and refused to go out, and then the alarm decided to keep going off, and even disconnecting the battery within the 15 secs after switching the ignition off, refused to silence it. After approx an hour of alarm activations, it just stopped, but the interior light refused to go out. It eventually did after about a further hour, but after another 15 mins or so came back on without me even going near it   It the went out again  and as I write this is stil out....
I think the next thing is to put the c/l  ecu from the donor car back in, and see if the interior light and alarm gremlins come back. If not, then the original ECU must be faulty - surely (?) - if they continue, I'll have to look elsewhere.....but where?
I was just curious really when the keys found to be working ok, whether the original ecu would work too.....
To be continued..

[TheBoy]

I agree, put donor one back in, and keep it in for a considerable period (months), and if it doesn't cause issues, keep it in.

Generally when a circuit board has suffered water ingress, you can't just dry it.

[johnnydog]

Thanks TB. I'll post how I go on...

[johnnydog]

It's now over 6 months since I fitted the c/locking ECU from the donor car with the key fob parts from the donor car with my original key blades, and the central locking has behaved itself since operating as it should. My interior light and light switch / key in buzzer issues have also gone away. All, I presume, down to earlier water ingress from the sunroof drains (outlined in another topic). The 'new old stock' central locking ECU I sourced from Italy, although not needed at the moment, was still worth getting - just in case...

[cam.in.head]

yes absolutely this is true !     at work we wash and dry in a temp controlled enviroment  many electrical items.( electrical windings ,controls,boards etc) to rid them from dirt or oil contamination and providing they havnt been switched on whilst contaminated they usually survive but if something has suffered ingress and been left for a while ( or powered up) the chances fall drastically especially if corrosion or an electrical tracking path has occured.
this will affect many car control units or wiring considering the atmosphere they live in and damp,extremes of temp etc its a miracle they work at all.
the fact that many circuits and ecu's look for a definate on or off signal can be mislead as lots of control units will see a circuit as commanded on even if theres a resistance in it and so can turn something on by detecting a signal present even if its just a high resistance signal due to an earth leak .
think of it like a relay control . a 12volt relay doesnt necessarily need 12volt to turn it on .some may well turn on as low as 6 volts or so .and some high resistance logic circuit inputs can falsely see a switch-on signal that should be 12v but may only be a few volts in reality with a load applied !