AWedder999 Posted December 1, 2007 Report Share Posted December 1, 2007 Hi I have developed an ECU related 'Safe Mode' / 'Limp Home' problem in an '02 - after standing, the problem occurs prior to a reasonable warm up period - its always on the restart that this problem occurs. Audi main dealer took £500 off me for saying that the cover box was cracked and was allowing in moisture - they replaced the box and since thin I get the Safe Mode everytime the car is started, After running it for a few minutes and trying several more times it usually comes right and is perfectly drivable, until the next time it has stood for a while - then, same routine all over again. Having looked under the bonnet I do see that there is always a lot of condensation on the lower surface of the bonnet... Have drained the wheel arch tubes and made sure that the main drains under the aircon intake box are clear - they are. Been back to the main dealer and they have run more tests - they get error codes related to start-up cycle with a 'Short Circuit to Terminal B5' - this boils down on their computer generated solution to me needing a new ECU. I find this hard to accept, given that once the car is warmed up it works fine - so there is nothing intrinsically wrong with the functioning of the ECU. Audi now want £1,100 for a new ECU for the Gearbox, but cannot promise that this will fix the problem. Otherwise, the car at 55K miles is perfect, but I am forming an opinion that I should dump it and get something else, as the forums are full of electronic problem issues and people are saying that these are a one way street to losing money... Any bright ideas out there for this 1st time user of this website community? Thanks Link to comment Share on other sites More sharing options...
alera Posted December 1, 2007 Report Share Posted December 1, 2007 IT s8 breaks a8s. Maybe he could source you a used ecu for less that the dealer. I am not sure how much work is involved in replacing it again maybe he will be able to elaborate. If you are going to sell it with the fault its going to seriously effect the value. Unless you plan on ripping someone off Link to comment Share on other sites More sharing options...
Figure11 Posted December 1, 2007 Report Share Posted December 1, 2007 Hi and welcom to the forums. IT_S8 does indeed break A8s and he is very much the Guru this side of the pond for these cars. Have you tried looking through audipages? http://www.audipages.com/ There maybe something there. Regards Mike Link to comment Share on other sites More sharing options...
IT_S8 Posted December 1, 2007 Report Share Posted December 1, 2007 I felt my ears burning... Sad news, but can't be too much wrong... I'm finding it hard also to believe you have an 'intermittent' ECU problem, unless warmth from the engine dries something out, but struggling to justify that as an answer. We'd need to know the part number on the ECU, on an 02 plate motor you probably have the sport mode type ECU (ie your auto box has PRNDS, not PRND432) which means I can't do an exact replacement - But If PaulW can upgrade his 01 car to have an 02 ECU for the sport feature, i fail to see why you couldnt use an 01 ECU to troubleshoot, which we do have 2 of.... Dont lose heart - They are fantastic cars, just dont use Main dealers to do any work on them and they are very cost effective Link to comment Share on other sites More sharing options...
NickGUK Posted December 1, 2007 Report Share Posted December 1, 2007 Just a query on your symptoms, When it goes to "safe" mode, does it actually stay in 3rd gear as well as "highlight" the dash lights ? If it still changes gear normally / as well as Tiptronic and the dash lights are highlighted, have the alternator Checked out properly. The gearbox ECU is very fussy about the voltage it gets, if its under, it can cause it to go into safe mode on the dash, although the car can still be driven normally both in auto and tip mode. Had these symptoms when i bought mine, hours diag at dealer and New alternator fixed it. BUT dont get alternator from dealer, GSF carparts can sell you one at a better price. Link to comment Share on other sites More sharing options...
AWedder999 Posted December 8, 2007 Author Report Share Posted December 8, 2007 Thanks for the post. I only get the problem on ignition cycle - the dash lights for all gears get shown in red and it only operates in Safe Mode until warmed up... then, after turning off and on a few times it goes Normal and all works 100% - until the next cool ignition cycle after it has stood a while... So, everything either doesnt work, or works perfectly...? Link to comment Share on other sites More sharing options...
AWedder999 Posted December 8, 2007 Author Report Share Posted December 8, 2007 Thanks for the post. It started with the dealer suspecting damp as the problem - they found a crack in the cover for the box housing the electronics and replaced that at the 1st visit. since then the problem has turned from being 'solid' to happening only during the cold ignition cycle... their diagnostics say there is a Short Circuit to terminal B5 ( I think) and the compueter tells them to replace the ECM... As I now have the car quite usable when warmed up, I still suspect damp MAY be an issue, and if so it doesnt need a new £1,200 part to be fitted which works perfectly when warm.. As to your question, it does have the sport type - ie PRNDS lights.... ???? Link to comment Share on other sites More sharing options...
AWedder999 Posted December 8, 2007 Author Report Share Posted December 8, 2007 Thanks - me again! I have looked at Audipages - thanks for that tip. I found a long article on changing the gearbox fluid - towards the end there was in fact a reference to Safe Mode being, in that case, related to dirty/old fluid - this was apparently cured, except for a single occurence in the following 6 months. So, can you or anyone else point me towards a Specialist who can carry out the Fluid drain and refill procedure for me - I am not equipped to do this myself.. Thanks again for the support. Link to comment Share on other sites More sharing options...
charlie61 Posted December 8, 2007 Report Share Posted December 8, 2007 [ QUOTE ] So, can you or anyone else point me towards a Specialist who can carry out the Fluid drain and refill procedure for me - I am not equipped to do this myself.. Thanks again for the support. [/ QUOTE ] where are you in the UK Link to comment Share on other sites More sharing options...
beemerboy9 Posted December 8, 2007 Report Share Posted December 8, 2007 I remember the classic story from the press of an A8 gearbox going into limp-home mode (3rd gear only) because an under-carpet switch/connector was loose on the brake pedal. The brake pedal switch tells the gearbox to be prepared to change down. No signal, no gearbox! Link to comment Share on other sites More sharing options...
greyjag Posted December 9, 2007 Report Share Posted December 9, 2007 For what it's worth I had a similar problem and eventually found the ecu more or less full of water. The car went through some serious water up here in the great NW and it seems some less than professional repairs had been made by the PO. and water got shoved right in it. I was quoted way to much money to replace it so I took it apart and cleaned and dried it . Then a carefull resealed it and polished up the contact pins. Haven't had another problem in 2 years. Link to comment Share on other sites More sharing options...
AWedder999 Posted December 28, 2007 Author Report Share Posted December 28, 2007 Thank you for responding - I am in an area that sits on the corner of Hampshire, Berkshire and Surrey... If you do know of any specialists who can do the gearbox fluid replacement in the proper way I would be very much obliged... Happy New year! Link to comment Share on other sites More sharing options...
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