Builder22 Posted August 3, 2008 Report Share Posted August 3, 2008 Hello there, I'm new to this forum and relatively new to A8s (I’ve been coveting them from afar for a long time J) I took the plunge recently and purchased a 2000 A8 4.2 (94,000 miles) however I have run into a spot of bother. The first indication of a problem was a couple of days ago, all of the transmission lights lit up red, there was a large "shunt" experienced when putting the car into reverse and a smaller but still noticeable one when engaging drive. In addition the car was extremely sluggish when pulling off. After some digging around on this and other forums the pants were scared off me as most pointed to a potentially terminal transmission problem with similar symptoms. Anyway to cut a long story short the car is currently in Limp home mode, lower down gears are not being used hence the sluggish response. I brought the car to a mechanic friend of mine and we checked for error codes in the transmission and found the following: 18232 P1824 Pressure control valve 3 – N217: open short to ground 18238 P1830 Pressure control valve 4 – N218: short to B+ When we cleared the codes the dash readouts when back to normal (red lights went away), but when I started the engine of course the car reverted to limp home mode and the red transmission lights returned. I suppose I could be described as “mechanically challenged” (i.e. I can do some bits and pieces but wouldn’t be brilliant or anything) so my following questions may be somewhat naïve. 1. What I’d like to know is has anyone experienced these errors with their A8, if so how costly is this likely to be to put right? 2. What is my next step, do I bring in the error codes to an Audi dealer and say tell me what to do to put this right i.e. purchase the necessary new parts and have them installed. 3. From the codes above it would appear that these are “simple” electrical problems, does anyone know if this is correct? Any help, advice, or guidance on this would be greatly appreciated. Link to comment Share on other sites More sharing options...
cruiser647 Posted August 3, 2008 Report Share Posted August 3, 2008 Hi ya! At that mileage, I'd book the car in (or get your mechanic mate) to check up the procedure on Audipages.com and change the auto transmission fluid. Drop the tranny belly pan and clean out the sludge/swarf and then refill to the procedures. Get the proper Audi fluid for it though. Whilst there, change the MAF - (mass air flow meter). When it starts to go wrong, it gives out duff messages, which confuses your autobox. 300 BHP and torque going through a confused autobox can cause it to die - expensively. Good luck! Link to comment Share on other sites More sharing options...
Builder22 Posted August 4, 2008 Author Report Share Posted August 4, 2008 Hi cruiser647, Thanks for the quick response, the transmission fluid and associated filters were changed approx 10,000 miles ago - do you think I should change again so soon? In terms of the mass air flow meter from what I have been seeing on this forum it can cause many gearbox issues. Do you feel that the fault codes could be as a result of a dodgy MAF? And if so do you think there is any point in investigating further the fault codes the diagnostic test turned out? Or just replace the MAF itself? Do you know if this is an expensive job and would I need to source the replacement part directly from Audi? Thanks again. Link to comment Share on other sites More sharing options...
cruiser647 Posted August 4, 2008 Report Share Posted August 4, 2008 The MAF will be about £80+ (max of £130+). You can get them from the VAG stealer or exchange from an indy VAG parts dealer. Only takes about 10 mins to change yourself. Try looking up Murray's in Hatfield on Yahoo, if you are in/about Herts. Link to comment Share on other sites More sharing options...
DJStrange Posted August 4, 2008 Report Share Posted August 4, 2008 Thing is with the MAF, it would be firing error codes if there was a problem? A bit expensive/pointless to replace it if it doesn't show errors? Mine was throwing up errors along the lines of "mixture too lean" and "misfire on ... cylinders". Also the gearbox was throwing up errors that it didn't know what gear to select. Those errors cleared once I replaced the MAF, but I still have a few funny gear changes to contend with yet - I suspect whoever did the last gearbox oil service didn't do it right on mine, so I've yet to check the ATF levels or just redo the service for peace of mind. If that doesn't cure it, I think I'll get the selector switch replaced inside the box, as mine still doesn't go into limp mode and has only done a mild thud into gear a couple of months back. If it's not throwing up MAF errors, I wouldn't bother changing it IMO. Welcome to the forums by the way - there'll be more brainboxes along shortly no doubt!! Link to comment Share on other sites More sharing options...
DJStrange Posted August 4, 2008 Report Share Posted August 4, 2008 If the MAF is throwing up error codes, a re-conditioned one can be bought from autotekelectronics.com for about £82 all-in, including delivery (that was a MAF for an '02 S8 - Bosch reconditioned). Not sure if anyone's got a cheaper supplier though? Link to comment Share on other sites More sharing options...
cruiser647 Posted August 4, 2008 Report Share Posted August 4, 2008 Thing is with the MAF, it would be firing error codes if there was a problem? A bit expensive/pointless to replace it if it doesn't show errors? Mine was throwing up errors along the lines of "mixture too lean" and "misfire on ... cylinders". Also the gearbox was throwing up errors that it didn't know what gear to select. Those errors cleared once I replaced the MAF, but I still have a few funny gear changes to contend with yet - I suspect whoever did the last gearbox oil service didn't do it right on mine, so I've yet to check the ATF levels or just redo the service for peace of mind. If that doesn't cure it, I think I'll get the selector switch replaced inside the box, as mine still doesn't go into limp mode and has only done a mild thud into gear a couple of months back. If it's not throwing up MAF errors, I wouldn't bother changing it IMO. Welcome to the forums by the way - there'll be more brainboxes along shortly no doubt!! They don't always throw up error codes when they are not working properly. Link to comment Share on other sites More sharing options...
Builder22 Posted August 4, 2008 Author Report Share Posted August 4, 2008 Hey cruiser647 and DJStrange, Thanks again for the responses, I’ve been doing some more digging in terms of the original error codes and this is what I’ve found: 18232/P1824 - Pressure Control Valve 3 (N217): Open/Short to Ground Possible Causes Wiring from/to Pressure Control Valve 3 (N217) Open/Short to Ground Pressure Control Valve 3 (N217) faulty Possible Solutions Check Wiring from/to Pressure Control Valve 3 (N217) Check Pressure Control Valve 3 (N217) Check Measuring Blocks Special Notes Pressure Control Valve 3 (N217) might be referred to as Solenoid Valve 6 (N93) Start with checking connectors for corrosion or water damage, in case of 01V transmission pay special attention to 16-pin connector between valve body and wiring harness. 18238/P1830/006192 - Pressure Control Valve 4 (N218): Short to Plus Possible Causes Wiring from/to Pressure Control Valve 4 (N218) Short to Plus Pressure Control Valve 4 (N218) faulty Possible Solutions Check Wiring from/to Pressure Control Valve 4 (N218) Check Pressure Control Valve 4 (N218) Check Measuring Blocks Special Notes Pressure Control Valve 4 (N218) might be referred to as Solenoid Valve 7 (N94) Start with checking connectors for corrosion or water damage, in case of 01V transmission pay special attention to 16-pin connector between valve body and wiring harness. Do you think these are worthy of further investigation or would it be simpler and cheaper to get a new MAF (with the current millage on the car should I be doing this anyway?) and see if that solves the problem? Additionally thanks for the info on the reconditioned MAF. As an FYI I am based in Ireland so unfortunately there does not appear to be as many local specialists as are available in the UK . Link to comment Share on other sites More sharing options...
PsYcHe Posted August 4, 2008 Report Share Posted August 4, 2008 Not an expert on boxes, but this looks like there's somethign wrong with the valve body in the gearbox itself. It's possibly they've caught something when they did the 'box last time. I'll ask on the audiworld forums as Tozo the A8 gearbox Guru is a regular there... Link to comment Share on other sites More sharing options...
Builder22 Posted August 4, 2008 Author Report Share Posted August 4, 2008 Cheers PsYcHe, much appreciated Link to comment Share on other sites More sharing options...
PsYcHe Posted August 4, 2008 Report Share Posted August 4, 2008 Current thoughts point to the F125 switch being faulty or loose, possible faulty ECU (just in front of firewall on right hand side of engine bay), or the solenoids in the gearbox. AudiWorld Forums: Tranny issues... Simple Cabling, or VB Replacement is the URL to the post.. You don't have to register in order to read the posts there... Some of the info there is pretty awesome. Link to comment Share on other sites More sharing options...
Builder22 Posted August 4, 2008 Author Report Share Posted August 4, 2008 Hey PsYcHe, Thanks a million for the quick responses, please pass on my thanks to JimR, jfrahm and Angus on Audiworld too. Couple of questions (sorry ) the F125 switch, what is this? In terms of the ECU I assume this to be the transmission ECU and if so this was replaced (previous owner indicated that this was replaced due to water damage. He noticed a nearly constant clicking in the transmission and had the ECU replaced) about 12 months ago. If it is a solenoids issue do you know if this is costly to put right. Apologies for my lack of knowledge and all the questions. Cheers B Link to comment Share on other sites More sharing options...
PsYcHe Posted August 4, 2008 Report Share Posted August 4, 2008 The F125 switch is a magical beast located deep in the underbelly of the Audi creature... It controls many functions, but usually it screws the transmission up in a manner not unbeffitting a Monty Python script. Search on yonder audipages.com (audipages A8 F125 Transmission Switch Replacement) and you shall find the location of this weak spot in the armour of the mighty Audi. Armed with spanners, sockets and a vast array of sweary words shall you conquer the beast! Or find a garage to do it for you The ECU is the transmission ECU.. It might be worth checking that there are no corroded connectors and they were all cleaned properly, or that there has been no further water ingress as the drains may not have been cleaned properly (again.. See audipages.com for the instructions). Link to comment Share on other sites More sharing options...
Builder22 Posted August 4, 2008 Author Report Share Posted August 4, 2008 Thanks PsYcHe , I shall begin the quest... but if any of you knights out there have any more tales of slaying Transmission monsters like mine please don't hesitate to share... B Link to comment Share on other sites More sharing options...
Builder22 Posted August 12, 2008 Author Report Share Posted August 12, 2008 Hello all, I have an update on my A8 and a strange one at that. I have not been driving it since it started to exhibit the limp home characteristics as I didn’t want to be doing an unnecessary damage and to be honest when it is in limp home mode it is no fun to drive. Anyway to cut a long story short… I am bringing the car to an independent specialist tomorrow so was doing some “valet” parking around the house to ensure an efficient departure in the morning. I was just reversing the car back into the drive (I need to climb over a small kerb) and was gingerly completing the manoeuvre. Got over the kerb and about half a yard later the car cut out. I was suddenly thinking that things were about to get terminal for the gearbox etc etc. (I know that was a bit dramatic ). So when I turned the car over again low and behold all the drive letters were back to normal. The car had knocked itself out of limp home mode. So I took it for a spin and it was behaving as it should. I am still planning on bringing the car to the specialist tomorrow and ensure that the fluid levels etc. are ok and to check the output on the computer. I also think it might be no harm to replace the MAF too while I’m at it. Just because it is not now in limp home mode it doesn’t mean that the problem has been resolved. I was talking to a guy in Automatic Transmissions (Welcome to Automatic Transmissions. We specialise in automatic gearboxes, reconditioned gearboxes, automatic transmissions and motor gearboxes. We stock many manufacturers gearboxes including subaru gearboxes, alfa romeo transmissions, renault gear b) today and got speaking to Andrew. I must say he was a very good guy and suggested that my problem definitely sounds electrical. He also kindly offered to speak to my local specialist and discuss anything if needed. I thought this was terribly nice of him. That’s the update for the moment – I just hope I don’t start the car in the morning and find it is back to the bad ways again. More to follow I’m sure. B Link to comment Share on other sites More sharing options...
harpersimon Posted August 13, 2008 Report Share Posted August 13, 2008 The exact same Andrew and company that have been chanted on there as fabulous people before.. and where I am going.. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now