My S8 box.....

Adrian E · #1 29th December 2010, 09:48 PM

Folks

Have noticed that occasionally I get all the gear shift lights coming on with a red background, so you can't tell what you've got engaged without looking at the shifter.

Am I right in thinking this is an indication of limp mode?

There's no lights on the dash to accompany the DIS going all red on me

Sometimes it's done it when I've just started the car, other times after I've moved off. Generally restarting the car seems to clear it.

It did it this evening when I needed to move the car to get the other one out and seemed a bit less keen to react to throttle than normal. Since I'd cold started it I didn't want to cycle the ignition just to prove a point.

Under normal driving the shift is extremely smooth with no hesitation when selecting gears, or moving the selector.

Where should I start to look to pin down any issues? Could this just be low fluid?

I have a friend who can check the fluid level and vag-com the car, but he's not back at work till 4th jan. From past experience with my Passat if I drive to his place I'll have to leave the car sitting for about 4 hours before it's cool enough to do the fluid check, which isn't ideal with an 8 month old in tow.....

Adrian

topgolfer1 · #2 30th December 2010, 10:24 AM

Hi Adrian,

Sure sounds like limp mode,my previous A8 went into that mode, but that was due to the brake pedal switch being faulty,As we need to depress the brake pedal to engage the gear stick,thats when mine used to go into limp mode,not every time but occasionally.So not gearbox related as I had assumed,I think we always think the worse,with the well documented gearbox issues.

Needs to go on the computer or vagcom really

Rich

Conan_the_Librarian · #3 30th December 2010, 01:02 PM

I concur with Rich. I have a similar problem on the project car. Only in 1st but it goes to limp mode and is cleared by switching off and on. VCDS is showing an intermittent fault on the brakes switch (not the brake light switch).

Singh · #4 30th December 2010, 01:09 PM

Adrian, is this the avus S8 that you have just recently brought? I'd get it checked out sooner rather then later as I'm sure the trader that sells it to you has some sort of legal responsibility towards the car if its faulty so soon after sale. I hope its nothing serious, but when the gearbox is concerned its better to be safe then sorry. If you haven't already, I'd recommend a Warranty Direct policy.

Adrian E · #5 30th December 2010, 06:40 PM

Hiya

Thanks folks - basically not much to tell without vag-com'ing it to see what comes up then.....

It is indeed my Avus car - I don't have a warranty as I knocked too much off the price to get one, so it was sold on a 'trade' basis - my invoice has 'no warranty applied or given' written all over it! I doubt I'm looking at £1100 expense given it's generally working fine (touch wood!) and that was the cost of the warranty they were offering.

Will have to wait till my mate's back at work, or I'll pop it down to Camspec on Manor Royal and ask nicely if they'll wack it on theirs and see what pops up.

#6 31st December 2010, 07:55 AM

My 8 does a very similar thing. When starting it occasionally goes into the all red dis mode but doesn't drive in limp mode if i drive it like that. The gears shift fine and it only appears to be the dis that is any different. I can easily get rid of it by restarting the car. It probably does it once every 10 starts (if that). I also find that if I start the car like a diesel (pausing the ignition before cranking the engine) then it doesn't do it it at all. I have no idea what is the problem until I can get it to my local VCDC specialist. Interesting info about the brake pedal switch though.

Jon

Adrian E · #7 5th January 2011, 07:01 PM

Took the car to my mate's work today (QST) and he checked the fault codes - can't remember the precise description of the fault, but it's basically the sensor on the side of the box which tells the gearbox what position the gear selector is in. It obviously disagrees occasionally with the sensor believing one thing but the mechanical lever has selected something else - talk about a pointless bloody sensor!

Apparently a new sensor is about £130 plus about 2 hrs to fit as the box has to be dropped down to access it. Since I'm planning on having the gearbox oil and filter changed in May when the next service is due I think I'll wait till then, unless it gets much worse.

It does at least confirm that this is only likely to happen when I shunt the car about and would potentially explain why the gearbox doesn't seem to go into proper limp mode and still changes gear OK. Sounds like yours is the same Jon?

At least it's nothng major internal to the box, which I doubted it would be as it seems to behave perfectly.

Adrian

PsYcHe · #8 5th January 2011, 08:18 PM

F125 switch by any chance? If so, then I'm sure the procedure is on audipages.com.. Might also just be needing cleaned as I think that was a problem with some.

Singh · #9 5th January 2011, 09:02 PM

Glad to hear it's not serious as honestly, I think your S8 looks fantastic. I want it!

Adrian E · #10 5th January 2011, 09:05 PM

Quote:

Originally Posted by PsYcHe

F125 switch by any chance? If so, then I'm sure the procedure is on audipages.com.. Might also just be needing cleaned as I think that was a problem with some.

Yep, that's the jobbie! I'll have a look - at my mate's labour rates it might be cheaper to clean it, but it's a lot of ball-ache to get it out and find it's still not working when put back in.....