PSM on/off auto gearchange differences

[gasguzzlingV8]

Hi

I have a question please I wonder if someone can answer?

I have a 2004/05 4.5V8 Twin Turbo, Tiptronic. When driving normally, leaving the car in normal D (Drive) the car is quick to shift gears between 2000 and 3000rpm, going up the gears as quickly as it can, often leaving me in too high a gear and being very sluggish.

I've recently noticed, if I turn off the PSM button, the car shifts alot later in the revs, between 3500 and 4500 and in doing so, always sits just on the turbo and feels so much more responsive.

flick the PSM back on, and the car returns back to its sluggish ways, trying to climb the gears far too early.

If I drive the car in manual/tiptronic (I do the majority of the time once the car is warm) I tend to drive it changing between 3000 and 4000 rpm. The gearbox is meant to remember the way I drive and respond accordingly, however doesn't seem to be learning??

I do wonder if its the underboost (boost leak) problem I've been trying to get to the bottom of, is affecting it, by the car flipping into limp home mode and wiping the gearchange memory?

I'm showing no error codes on the iPhone Rev application, however am currently unable to stick the durametric program into the car as I have switched from PC to Mac.

I've had the car into the dealer and mentioned the early gearchange and they said sometimes the gearbox settings can stick and reset it for me, however it doesnt seem to make a difference.

Can anyone shed any light on this? ... does the car have a different engine / gearshift map without PSM on??

Thanks

Chris

[wvicary]

Yes the vehicle reads different maps with PSM on and from what you've described your vehicle is operating normally. When trying to make it learn your driving style it's important to manually shift at the RPM you like but also apply lots of throttle to get to said RPM.... don't be gentle on the gas and it will learn much quicker. It will retain your driving style so long as you drive more aggressively, start driving economically again and it will soon revert back to the factory settings.

My Durametric works fine on my Mac.

Another thing to consider is if the battery is weak the adaption values can easily be lost.

[gasguzzlingV8]

Hi wvicary, thanks for that. How are the maps different? do you know?

How long do I need to drive before the gearbox learns my shift patterns?

Just recently changed the battery, because it was weak after I killed it after a long lay up. it's getting a good charge from the alternator, so should be OK.

How do you use the Durametric program with you're Mac? Do you run parallels, or something similar??

Thanks

Chris

[wvicary]

I'm not sure how long it takes to relearn but after a day of city driving(40 km??) it learns on my Cayenne.

If you check out Durametrics website it has some info on running the system on a Mac. I'm running on a older(2003) PowerBook G4 using Virtual PC and it seems to work ok. My friends Intel based Mac runs it with not problems at all but I'm not sure what he's using.