Hi Del,

Yeah. I've checked / topped up the oil. I did that last week before I went anywhere at distance. To be fair it ran fair with slightly low oil (it took about 400ml over what i'd already put in at an angle)

Since it's quick and easy to play with the TCU's and I have 3 I thought i'd have a look at what happens using the other two for comparison

http://farm4.staticflickr.com/3734/1...629bc1e7_b.jpg

DG from my dead FL S8, old BG with solenoid fault, New BG


Old BG - Solenoid error
http://farm8.staticflickr.com/7416/1...123e36b6_b.jpg

DG - Software not recgonised
http://farm8.staticflickr.com/7332/1...1290cff8_b.jpg



New BG, Before Fault
http://farm3.staticflickr.com/2852/1...0d8fc020_b.jpg

New BG, After Faulthttp://farm4.staticflickr.com/3682/1...e1fbcf29_b.jpg

Notice that with two of the boxes limp mode seems to be 4th gear. I tried the DG box after the New BG which gives 5th with the idea that maybe it did work at all and would stay in the last gear, but nope it gave 4th too.

Oh and i've made a minor error. The boxes are BL not BG!

Man that sucks,

I see from your screen shots that input speed matches engine speed which is what i get when i select drive on mine, so would say thats normal behaviour.

Unfortunately mines a different gearbox to yours so even if I logged it through the different gears it wouldn't tell you much.

But i'm puzzled why your input rpm would be 0 when its in limp mode, unless that's how its meant to be???

Hi There,

No idea on the 0 RPM in limp mode, though I was probably had my foot on the brake. The rpm sensors are working fine given other readings so i'd ignore.

Last night however saw me loose power in 4th gear and I now have no forwards momentum at all. I've tried the other TCU's this morning and nothing.

Oddly reverse is fine and I ended up reversing a couple of miles back to my factory where I had a spare Smart Car which go me home!

No Idea at all where I go from this ????

have you checked the F125? Could be that the box is foobared though.

Thinking about it some more its probably meant to be like that on the speed sensor as that input one probably locks up to send power through to the planetary for 4 gear (Limp)

It wouldn't be anything to do with the MAF by any chance as I have read elsewhere that it can screw with the box if its not right.

Might be worth a quick disconnect to try?

It won't hurt at least... If it's just that, you might be lucky enough to save the box in time.

Hi There,

For the 10 minutes it too to disconnect and reconnect the MAF sensor, it was worth a shot, but nope. No change to getting any forwards movement.

I doubt it's the F125 switch. I did disconnect it when under the car and actually the engine won't start without it which surprised me. I have no fault on it and under VCDS on measure blocks you can check it's operation as it has a 4 digit binary code (0101 etc) and you can cycle through all of the digits by the various positions on gear stick. This to me would say that it is fully working. Alas.

I am wondering if it is the torque converter, but i'm guessing gearbox rebuild as there is no forwards movement, but it will reverse.

More documentation

5HP24 repair manual NOT 5HP24A which i dont have..

Not sure if covered in the early post but links below from a chap who has repaired two of these boxes with good write ups.

Thread here re S8 :

http://www.motorgeek.com/viewtopic.p...46685&start=50

And RS6 C5 (same box) diff problem here :

http://forum.rs246.com/viewtopic.php?f=2&t=104077

Hi there,

Thanks brasiliangringo - There is a load of information there. I'm having a good read through the PDFs and working out quite what does what +++

Is your old S8 gearbox in working order? You have its TCU, you could just swap them both into your new car?

Goran,

I love the "JUST" in that sentance. Yeah. I do....it's a ECX vs a BFG iirc and the controler is a BL vs a DG. From what i've seen / worked out the FL cars gearbox controller (DG) won't work with the PF ECU, however the PF gearbox controller (BL) should be fine with the FL gearbox as the only thing it interfaces with is the valve body and they certainly do work.....I'm not sure of the exact 'upgrades' ZF have made between them but they so far seem minor on the valve body.

I do wonder if there is any difference in mechanical interfaces as the FL has the 40v engine and the PF the 32v.

I must admit it's the lack of ramp access that is making me retisent in swapping gearboxes....It certainly doesn't seem an easy job!

Lee

Out of interest, did those donor ECUs with different P/Ns actually work without throwing the 'ECU incorrectly coded' error message in VCDS as normally thats what you get when you swap different number ECUs in - ie they tend not to work.

brasiliangringo - Nope. The DG one from the FL car threw an error, hence I got a BL from a8parts. Irritating as i'm sure it's just the software in the box. I'm guessing you have to pair the gearbox TCU and the engines ECU or they have a hissy fit as reading the docs they swap information.


Interestingly i just tried removing the TCU completely as the Docs mention a second form or LIMP HOME that has nothing in the PRND432 window. The car starts and will go into reverse and move, but I have the same lack of forwards :-( It was expected I guess.

Shame that with VCDS etc you can't pro-actively test things. For example set the solenoids or force a gear!

BTW - Just found http://lubricants.org/index.php?rout...earch=%2071141

£100 for 12l and £140 for 20L of Mobil ATF LT 71141

Hi Lee, yes, "just" was a bit optimistic having see the posts about the removal process. Also I completely forgot your new car is PF, my mistake.
If I recall some quattroworld posts, PF has a 10-blot pattern compared to FL 8-bolt pattern?

"If I recall some quattroworld posts, PF has a 10-blot pattern compared to FL 8-bolt pattern? "

What quite does that mean ??? I'd certainly like to verify and get my head round it before potentially getting mechanical!

Ta,
Lee

As far as I know manual 01E gearbox can be mounted to both PF and FL so the automatic swap from PF to FL should be possible as well. I think 10/8 bolts are for torque plate/flywheel. So there might be issues coupling torque plate and torque converter. Maybe somebody from A8parts can comment.

Yes what Ainarssems said, its the flywheel/flexplate mounting bolts, 10 PF, 8 FL, so if the PF and FL flex plates are different it could be a pain.