P964C2

Hello, please could anyone suggest what's wrong. 100k miles and recent ATF change and filter clean, the car suddenly would not shift back up into 4th. It said 4th on the manual light to th right on the speedo, but it was in 3rd. Moved it into D and still the same. After having come to a stop and then setting off again it was fine. This was on a long journey. It recently had the speedo sensor on the gearbox changed as it had flashed up the gearbox warning light. Has anyone any experience of these problems please? Hasn't happened since, but I expect it will. Thanks in advance.

P964C2

Well the tiptronic warning light came on today - I had it in 2nd manual and accelerated upto about 4K revs, it jumped into 3rd and the "D" light came on instead of a manual selection number. It drove fine though in D. Came to a stop, switched off and on, and its been fine since, and the warning light went out.

Is it the gearbox that's at fault? How reliable are the tiptronic ECU's?

Please can anyone advise? Does anyone rebuild these units in the UK?

Thanks.

CBR786

HI

driver transmissions in Birmingham used by several porsche specialists

something to check before hand

tyre pressures all round need to be equal
are all your tyres on the same axle same brand i.e front both tyres need to be same make always change tyres in pairs if one tyre has more wear then the other on the same axle can throw abs out which in turn has a knock on effect to tip ecu

oil cooler on tip box could be clogged up I am not sure if 964 tip boxes even have oil coolers ? but if they do needs looking at also fluid might be low or stick valve on solonoid which can all give your symptoms. I am no linked with drivers tranmissions but have used them in the past and was happy with quality of work.
I asked for guy called Bob proprieter along with his brother and they looked after me on my 996 tip which I know is not a 964 lol I have a manual 964 luckly

RichieRoo

Hi.

Just to be clear; you say that it "stuck in 3rd"... this wasn't just the gearbox
going into 'limp home' mode was it?

There are a number of posts regarding this issue. My car does it from time
to time.

If the ATF change was done with the correct fluid and to the correct level,
it shouldn't affect the operation of the tip. I did mine a little while back and
you don't have to disturb too much.

Rich

jeffnudd

It maybe a good idea to check the level again in case you have a leak, like someone has already said it could be a sticking solenoid possibly?
These gearboxes do have coolers, infact its mounted behind the oil cooler in the right hand front wing, to be fair i dont think you would have any problems with the cooler because the veins are quite large and the most likely thing to clog up because of old fluid is the gear box filter whitch should be changed when the fliud is replaced.
The filter is situated on the base of the valve block inside the tip gear box, it is a fairly simple job to do.
I wouldnt get too alarmed as these boxes are really robust.

P964C2

Thanks for your respective answers.

I don't know if it went into 3rd gear limp mode as it managed to change down OK. Does limp mode mean it locks into 3rd or that it just won't go above 3rd? Regarding the ATF change and filter cleaning, it recently had this done but I will check the level again.Yes I have heard this boxes are robust. Can the same be said for the tiptronic ECUs?

Thanks for the recommendation of the garage.

Regards.

CBR786

I think unless you do something crazy like get ecu wet or jump start car with battery unplugged or 24 volts or something drastic the ECU's rarely go wrong unless moisture of some sort has corroded some of the tracks which can be repaired but buy an ECU specialist. more likely went into limp mode I think Limp mode does stop car changing up I am not sure as I own a 964 manual box but I do have a 996 TIP. I know on my 996 if it goes in limp mode carwont go into 5th gear & the D light and 4rth gear light start to flash like a christmas tree.

jeffnudd

It does seem a bit coincidental that is has only happened since the change, it may be an idea to ask the garage what type of transmission fluid was put into the gearbox i use ATF Dextron 3. works in pretty much all auto gearboxes.