Central Locking Faulty and Battery Draining - ECU?

[986volante]

Okay this is more than likely my fault for not getting my bulkhead drain grommets sorted out properly last autumn (they were blocked and causing water seepage into the cabin but when I was trying to clean it out I managed to push the old n/s grommet into never-never land.l bought a replacement and then did the same again! (To be fair it is a ba***rd to access as you'll know if you're familiar with this). I intended to try and access the never-never land area by removing the inner wheelarch liner in the Spring - by the way, as a separate issue, does anybody know if that will allow me to access/ retrieve/ refit the damned grommet?

Anyway, onto the current issue.......the passenger carpet got wetter than I realised and although the ECU/ alarm unit seems positioned high enough away from the floor under the seat and is not covered with the carpet, I'm guessing that this has caused the problem that I have now. I.E. The central locking won't work now and only the drivers door can be locked with the key, plus the battery drains completely overnight.

I took out both the passenger seat and the carpet to have a look, but although there was some water (not that much as there is a small hole drilled in one corner acting as a drain!), the ECU/ alarm unit appeared to be dry.

Having tried to find a solution on various forums/ searches, I haven't seen this fault replcated or explained anywhere else, although my thinking is that it is actually the ECU which is the problem due to moisture ingress?

Anyone know if I'm right and if it is the ECU, what's the best solution please, repair (how?) or replace? I've read some stuff about a reprogramming issue with new units?

Any help much appreciated.

Cheers,

Tony

[Loren]

As your topic appears to be a DIY question (rather than a DIY Tutorial), we have moved it to the appropriate forum.

This is an automatically generated reply.

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[JFP in PA]

Okay this is more than likely my fault for not getting my bulkhead drain grommets sorted out properly last autumn (they were blocked and causing water seepage into the cabin but when I was trying to clean it out I managed to push the old n/s grommet into never-never land.l bought a replacement and then did the same again! (To be fair it is a ba***rd to access as you'll know if you're familiar with this). I intended to try and access the never-never land area by removing the inner wheelarch liner in the Spring - by the way, as a separate issue, does anybody know if that will allow me to access/ retrieve/ refit the damned grommet?

Anyway, onto the current issue.......the passenger carpet got wetter than I realised and although the ECU/ alarm unit seems positioned high enough away from the floor under the seat and is not covered with the carpet, I'm guessing that this has caused the problem that I have now. I.E. The central locking won't work now and only the drivers door can be locked with the key, plus the battery drains completely overnight.

I took out both the passenger seat and the carpet to have a look, but although there was some water (not that much as there is a small hole drilled in one corner acting as a drain!), the ECU/ alarm unit appeared to be dry.

Having tried to find a solution on various forums/ searches, I haven't seen this fault replcated or explained anywhere else, although my thinking is that it is actually the ECU which is the problem due to moisture ingress?

Anyone know if I'm right and if it is the ECU, what's the best solution please, repair (how?) or replace? I've read some stuff about a reprogramming issue with new units?

Any help much appreciated.

Cheers,

Tony

This is a common problem with cars the get water under the seats.

Under the seat is the electronic control module for the central locking system, which shorts out when it gets wet. Fortunately, it can be removed, opened up and dried out, sometimes requiring a new fuse that is in the module itself. Once dry and reinstalled, they typically go back to working fine.

Do a search on this topic, it has been covered extensively with pictures more than once.

[986volante]

Okay this is more than likely my fault for not getting my bulkhead drain grommets sorted out properly last autumn (they were blocked and causing water seepage into the cabin but when I was trying to clean it out I managed to push the old n/s grommet into never-never land.l bought a replacement and then did the same again! (To be fair it is a ba***rd to access as you'll know if you're familiar with this). I intended to try and access the never-never land area by removing the inner wheelarch liner in the Spring - by the way, as a separate issue, does anybody know if that will allow me to access/ retrieve/ refit the damned grommet?

Anyway, onto the current issue.......the passenger carpet got wetter than I realised and although the ECU/ alarm unit seems positioned high enough away from the floor under the seat and is not covered with the carpet, I'm guessing that this has caused the problem that I have now. I.E. The central locking won't work now and only the drivers door can be locked with the key, plus the battery drains completely overnight.

I took out both the passenger seat and the carpet to have a look, but although there was some water (not that much as there is a small hole drilled in one corner acting as a drain!), the ECU/ alarm unit appeared to be dry.

Having tried to find a solution on various forums/ searches, I haven't seen this fault replcated or explained anywhere else, although my thinking is that it is actually the ECU which is the problem due to moisture ingress?

Anyone know if I'm right and if it is the ECU, what's the best solution please, repair (how?) or replace? I've read some stuff about a reprogramming issue with new units?

Any help much appreciated.

Cheers,

Tony

This is a common problem with cars the get water under the seats.

Under the seat is the electronic control module for the central locking system, which shorts out when it gets wet. Fortunately, it can be removed, opened up and dried out, sometimes requiring a new fuse that is in the module itself. Once dry and reinstalled, they typically go back to working fine.

Do a search on this topic, it has been covered extensively with pictures more than once.

Thanks, I've just removed the ECU / Alarm module and it was a little wet on the underside but the fuse was okay, so I've put in on top of my CH boiler to dry out overnight and I'm hoping that tomorrow it will be "working fine" as you suggested might happen. If it is I owe you a pint at least! :)

If not :angry: I'll need a new ECU then and some advice about getting it coded. I did a search on this site as you said and did find some answers to the other stuff but not about replacing the ECU

[JFP in PA]

One way to "speed up" the drying process is to remove the unit's cover and rinse it out with dry alcohol (medicinal rather than consumption type), then let it air out.

Castletown Pale Ale, please.............. :cheers:

[986volante]

One way to "speed up" the drying process is to remove the unit's cover and rinse it out with dry alcohol (medicinal rather than consumption type), then let it air out.

Castletown Pale Ale, please.............. :cheers:

Thanks for that although I only have the drinkable kind :) - but it turned out that i was right and it wasn't wet at all inside - no obvious signs of moisture, rust or shorting - like new in fact! Nonetheless I left it on top of the CH boiler all night where it was nice and warm and not too hot.

I was very optimistic that just a small amount of moisture from condensation had caused the problem as it looks in such great condition and thought all would be well once reinstalled.

Unfortunately having just returned from a long run to ensure that the battery was fully charged, the problem hasn't gone away and symptoms still remain - still not central locking or activating alarm and the battery will be draining away again now. I forgot to mention previously that the dash lights for the odometer and mileometer were permanently on and is clearly the cause of the battery draining of power. I'm surprised that they would be affected by the ECU though, not that I know diddly squat about electrics :wacko: .

Unless anybody has any other possible explanations for this happening, then I must now assume that I need to replace the ECU/alarm module.

I have seen one on eBay from a reputable source for £225 but I need to know that I have explored all the alternatives before committing to buying, not to mention that I will somehow need to get it programmed for my car. Will I have to go to a Porsche stealership to get this done, or are there any other ways of doing this please?

Meanwhile I'll be getting the grommet/ water seepage problem sorted to make sure it doesn't happen again!

Edited February 2, 2013 by 986volante

[JFP in PA]

If you replace the module, it will require programing with either a PST II or a PIWIS unit to accept your keys and be functional. If you go flea bay, be careful about how many of the "slots" (there are usually four) in the module have already been programed. Once they are all used, it is difficult to reprogram the unit.

It sounds like you definitely have an electrical “gremlin” in your system, which is causing the lights to remain on in the dash. This should also be addressed as it may relate to the issue with the central locking system as well. Quite often, we see strange electrical faults caused by failing ignition switches. What happens is the electrical section of the switch starts to die and things start not working or refusing to shut off. Fortunately, the fix is a quick and cheap one as the electrical section of the ignition is a $10 item here (Audi uses the same switch) and can be changed out quickly with a small screwdriver (it simply unplugs from the back of the ignition’s mechanical section). This problem is so common that carry we replacements in stock at all times. There have been a couple of detailed DIY procedures done on this, so you may want to do a quick search.

[986volante]

If you replace the module, it will require programing with either a PST II or a PIWIS unit to accept your keys and be functional. If you go flea bay, be careful about how many of the "slots" (there are usually four) in the module have already been programed. Once they are all used, it is difficult to reprogram the unit.

It sounds like you definitely have an electrical “gremlin” in your system, which is causing the lights to remain on in the dash. This should also be addressed as it may relate to the issue with the central locking system as well. Quite often, we see strange electrical faults caused by failing ignition switches. What happens is the electrical section of the switch starts to die and things start not working or refusing to shut off. Fortunately, the fix is a quick and cheap one as the electrical section of the ignition is a $10 item here (Audi uses the same switch) and can be changed out quickly with a small screwdriver (it simply unplugs from the back of the ignition’s mechanical section). This problem is so common that carry we replacements in stock at all times. There have been a couple of detailed DIY procedures done on this, so you may want to do a quick search.

Thank you so much for opening my eyes to another possibility - it sounds really promising, and logical too. So now I'm hoping that I've prematurely jumped to the wrong conclusion about the ECU. It makes absolute sense because you'd have thought the dash lights would have gone out once the ECU was removed and they didn't! So this may also mean a much easier and less costly fix..... fingers crossed.

I'll get the battery recharged and then disconnect the plug at the back of the ignition and if the dash lights go out then problem identified and I just need to replace the switch! I'll report back once I've tried that.

Thanks again!

Edited February 3, 2013 by 986volante

[986volante]

Yippee!!! (I'm not normally prone to such silly outbursts but this made me very happy!!!!)

Followed the instructions that I found after searching this site :-

http://www.renntech.org/forums/tutorials/article/24-996-ignition-switch-replace-just-the-switch-with-pictures/

- top notch and even I found it easy to do and in a short time.

I decided to test out whether the switch was definitely faulty before buying the replacement, so I proceeded as far as unplugging it to make sure I could actually do it, then plugged it back in, jump started the car and took it for a run to recharge the battery. Got back and unplugged the switch, closed the door and used the remote key fob to successfully activate the central locking again, and the dash lights also went out as they should.

!!!!!

So fault now proven and all I have to now is buy the unmodifed original ignition switch which I've seen for £12 +vat and fit it which I know won't take me more than about 15 minutes.

This forum is brilliant so thanks for all the help that I've received and also for offering it so swiftly!

Haven't seen my exact symptoms on this or any other website, so I also hope that the advice I've received here proves invaluable to others too!

Cheers Guys!!!

[JFP in PA]

Glad to be of help; next time I'm south of London on the M25 ring road, I'll take you up on that pint.................. :cheers:

[986volante]

Glad to be of help; next time I'm south of London on the M25 ring road, I'll take you up on that pint.................. :cheers:

Would be glad to, I'll PM my mobile number :cheers:

[986volante]

Just a quick update on fitting the new switch and a advisory word of caution to help you do it.

It would have been very easy to do this in a matter of 20-30 minutes if I hadn't experienced (through my own fault) a real problem with the grub screws that hold the switch in.

They are quite difficult to access, so a word of warning to anyone doing this - make sure you have or get a suitable screwdriver - you need either a jewellers screwdriver or a right angled ratchet screwdriver/ set, otherwise you will find it a pig to do (as I did, because I didn't have the right kind!) or totally impossible. In my opinion, I think the right angled type would be best - in fact I've just ordered one for future use! Only £3 too!)

I would also strongly recommend using the method described on this site and mentioned above. I would never had managed to do it by trying to crawl under the dashboard and straining to reach something which you can't even see from underneath! So accessing it through the air vent method is by far and away the easiest and quickest way to do this job. Why make life difficult?

Well, on to my next job of fiixing the leak now, which is of course what I wrongly thought had caused this issue in the first place - but luckily it has now cost less than £20, so a lot better than ten times that for the ECU!!!! Oh happy days! :clapping:

Edited February 6, 2013 by 986volante