R34 Tiptronic Issue - Limp Mode After Having Solenoids Replaced

[noexec]

I recently had to take my car in due to faulty solenoids (solenoid A error), turned out that there had been water in the tranny and needed a rebuilt so what needed to be replaced was replaced. However now with the new tranny / solenoids the car will still jump into limp mode. Car will start normal but as soon as it gets into 2nd/3rd it'll jump into limp mode. The error can be erased with the handheld device (while driving and in limp mode) but once you stop and take off again it'll jump back into limp mode each time.

- Trans has been replaced.

- soleniods been replaced.

- Wiring looks OK.

- Trying to see if another earth will help

- Could it be an issue related to the tranny ECU?

Does anyone have any ideas of what could now be the issue?

Looking around on the forums there seems to be no sure answer and yes... manaul conversion is a 'last resort'

[bubba]

At one stage I had a dicky earth clamp on the battery, some bumps would move it around, there would be a big lurch and the auto would drop in to limp mode temporarily.

So yes, dodgy earth could be the culprit.

What error code is it throwing up?

[noexec]

Solenoid A before and after, its odd that the car will go in limp mode everytime it gets into 2nd from standstill after the codes get whiped while driving.

Before I had the trans rebuilt the limp mode was 'normal' (for what it is) but now it seems to always just come up right away. However the car drives perfectly fine when not in limp mode

[turboedsloth]

Take it back to the place that rebuilt the transmission, you should have gotten some sort of warranty with it. How long ago was it overhauled?

[noexec]

It's just been done and is still at the shop, they can't figure out why its still going into limp mode

My guess is that its either an earthing issue or maybe the Auto ecu

Any one have any ideas?

[bubba]

The auto control unit is part of the ECU, not a separate unit like earlier models.

And if it's throwing the same error before and after the rebuild, that makes me think that whatever they did DIDN'T fix the issue.. I hope you're not paying for them to learn..

Edited February 22, 2011 by bubba

[noexec]

Haven't paid them yet!

They say rebuild is fine, auto electrician said the wiring seems ok, they've tested the voltage at the solenoids (have been replaced) which seems to be all ok and the earthing seems to be ok too. They seem to be out of ideas of what it could be so I don't really know what my options are. Send my ECU's out to get them checked or even try sending it to a specialist to have a look over?

When the errors are cleared the car drives fine so something for some reason is causing the error to pop up and jump into limp mode wether its faulty soleniods or something else lurking around.

Don't really know what direction to take this in or what my options are?

Edited February 22, 2011 by noexec

[bubba]

OK here's a little anecdote that might help shed a little light..

When I was playing around with NIStune'd ECU's in my car I was doing a lot of swapping of ECU's. If I just pulled the ECU out without bleeding any residual current in the system (i.e. not pushing the brake pedal after disconnecting the battery), it would throw up HEAPS of A/T errors including a bevy of solenoids and other stuff but nothing was actually broken. It was just the control module flipping out because I didn't discharge the residual current in the system.

The point I'm trying to make is that it *could* be an intermittent earthing or wiring problem somewhere and it sounds like the problem was there before the rebuild and the box probably didn't need new solenoids etc.

Try reset the ECU, if that doesn't work then the auto-sparky needs to be present when the problem is replicated. If it works for a while and randomly drops in to limp mode I highly doubt the TCM (inside the ECU) is the culprit, sounds more like a wiring/connector issue.

Edited February 22, 2011 by bubba

[noexec]

Update (have been too lazy to post), issue has been fixed. Although I told the mechanic to reset the ECU (he also said he had) I guess he mustn't have because the codes cleared up after a while of test driving it around. All good now