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996 Tiptronic Gearbox Fault - help

aerokit

Well-known member
Joined
4 Mar 2017
Messages
57
So...drove home about 65 miles last weekend. Having pulled into the driveway I noticed the 'P' and '4' lights on the gearbox dash display were flashing one after the other.

Took the car back out and discovered the additional symptoms:
1) the steering buttons aren't working now - up and down shift not functional in 'semi-manual'
2) the car is shifting down to 1st when slowing. In my ownership its generally always ever gone down to 2 and pulled off in 2. The shift down to 1 is noticeable as the car is still rolling sufficiently for 2nd gear so being in 1st you get a lurch forward when you accelerate again.

Did a google search and the flashing likes suggest the gearbox is in a 'limp mode'.

Certainly driving it, apart from the shift down to 1st it doesn't seem noticeably different, maybe a bit 'lethargic' but not what I'd expect of a limp mode.

The forums don't seem to point to a finite number of definitive causes. Tried my OBD scanner and that didn't read any faults either.

Has anyone had this?

or alternatively, can anyone reccommend a good garage in the West London-ish area that could diagnose?

Thanks!
 
Tell me about! Right on the eve of summer too :sad:

Thanks for the suggestion, have used PT in the past and had a mixed experience so was looking to try elsewhere if possible
 
Have you done an ATF and filter change? If not, then fingers crossed it'll sort the issue.
 
Yes, last year done by Portiacraft. Can't recall if it was fluid and filter but can't imagine why it wouldn't be... It shouldn't need doing after a year/5000< miles surely?
 
No it won't need to be done .. have a quick look at the other 'tip problem' thread I started, seemingly unconnected faults can affect tip gear selection.
Best of luck with solving the problem.
 
The gearbox has entered limp mode due to a fault .. this is a measure to protect the gearbox from further damage .

If you turn off the ignition and back on it should drive as normal until it sees a fault and then will again enter limp mode .

if it stays in limp mode regardless then its a permanent fault .

There Should be a fault code in the tip control unit but i would also check the dme for fault codes .

You have had the oil and filter done so its not that , im afraid there are many faults it can be from the box to wiring to the control unit ..

there is also the possibility of a maf sensor fault causing this .. hence dme fault code check and a look at the values for the maf sensor ..

Maf sensor .. actual value of 1 volt ignition on but not running ..

Running and when warm in the region of 18 kg/h .

Now then ..

When you move the gear lever is it stiff ? have you ever had any warning messages saying tip failure or gear not selected ?

There is a multi function switch on the side of the tip box .. if the cable pivots start to seize it wont move this switch far enough so it thinks the lever is in the wrong position .

Basically is the lever stiff to move ?

You are probably into a garage job im afraid as its codes and values we look at to find a fault like this .. but its not always a new box required so don't panic just yet .
 
I did a tiptronic box refresh (new filter, oil and other goodies) and got the Limp Mode .. Turns out the Fluid Return Pipe was a little loose and had allowed ATF to leak out, causing a low reading and thus putting it into limp mode.

Hope yours is as simple was mine
 

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