vwbrd

So, got my 14 CD 1 month ago and have driven it ~800 miles. I'm still not sure if this throttle behavior is expected behavior or not? It seems like the first 25% or so of throttle pedal movement gets you very gentle acceleration, and then there's an area that requires very precise delicate foot effort (call this 25-30% application), and then past that you get a LOT of acceleration. I've driven VW diesel's before (1.9TDI) and a 1.8T gasser and had no trouble accelerating constantly. It just seems to do more peppy driving without wide open acceleration is tough.

I'm taking it in this morning to get my new plates & a few minor fixes, so I will ask them, but I expect the SA to tell me it's normal. But maybe there's some adjustment? I'm guessing most will tell me it's a post-fix thing.

hotrod2448

I'm guessing it's hot in DFW right now and your car has had the emissions fix applied, right? If so that's a feature now for a lot of us.

Read through this if you haven't already, It's only a little over 400 pages :
https://rennlist.com/forums/cayenne-...ion-issue.html

You can scroll back through the last few pages and get the gist, hot weather creates a pretty severe hesitation in throttle response with the fix on a lot of diesels.

BenCD

There is, at least for the VW 3.0L TDI, a "throttle/transmission relearn procedure" where all the memorized shifting behavior is reset so the truck does not think that Miss Daisy is always driving.

I just floor mine enough so that my diesel engine and x-mission do not fall into lazy/slovenly-habits.

In SPORT-mode, fuggedaboutit, SPORT keeps the 400+ ft lbs of torque on hand at all times. Turbo Direct Injection=nice.

vwbrd

Hasn’t really been hot yet, only in the 80s. Maybe the cayenne thinks that’s hot. I have seen some of that thread while trying to understand the extended warranty.

Im not sure I’m talking about the same thing, though. If I stomp on it from a stand still, it goes with very little lag. And if I start slowly applying throttle, there’s no lag. It’s just trying to find an in between seems to require super-precise ankle control.

vwbrd

Cool. I will ask about this procedure today. I know I’ve seen DIY sequences for the PDK in other cars to reset it. Didn’t know it was possible for the CD.

BenCD

It is something like, accelerator pedal to the floor, turn key but do not start engine, wait 10 seconds, release pedal, and the x-mission/throttle will be reset and ready to learn how YOU drive.

You have nothing to lose by trying it and some do report noticing a/the change.

hotrod2448

I'm not sure what temp it becomes really obvious at. Last week it was 95° here and it was pretty apparent. This week it's been low 80's and it isn't bad but, still noticeable if you know the feeling you are looking for.

I think your description sounds a lot like how the lag behaves in that temperature range (at least in my vehicle). Stand on the gas. it goes. Drive like grandma and it can respond as expected. Drive like a normal human being when it's hot out and you feel it, especially from a stop or near stop. Typically in that case you apply more and more throttle waiting for the vehicle to respond and then you are met with way more acceleration than you really wanted. If you can resist the temptation to keep rolling into the throttle when you notice the lag and maintain a consistent pedal angle it will eventually begin to accelerate.

BrewDude

I'm noticing the same thing in my recently acquired 2016 CD. Definitely apparent in the Vegas heat this week.

Gonna try to do the relearn procedure, although I wonder if I can use my VCDS (if it'll actually pick up the TCM) and clear it that way.

BrewDude

This is the procedure from Club Touareg via TREGinginCO:

1: Car off.... key in the ignition
2: Car on.... engine NOT running
3: Press gas pedal all the way to the floor.... hold for 10 to 15-seconds
4: Take foot off gas pedal
5: Turn off car --- take key out of ignition
6: Open driver's door Close the door... start the T... take it for a drive... see how it works.

Ben were you also on Club Touareg? I was over there when I had my TDI but haven't frequented it until recently.

vwbrd

Back from the dealer. The SA told me the tech had never heard of a re-learn procedure. I said I’d seen others mention it online but didn’t know if it had a tech note or bulletin for it & she said she’d go search their database. She didn’t mention it again.

Leaving the the dealer I’m wondering if they didn’t do something? It may be a placebo, but it seemed I could give it a lot more throttle input without shooting ahead.

In in other news they gave me a new clock (not technically under warranty, but we discovered the second hand was missing on mine on the test drive & my salesman said he would get it fixed), replaced a rear vent that was missing a tab, and gave it a hand wash.

BenCD

Yes, I was/am BenTDI over there as I had a 2012 Touareg TDI before the CD.

I go check it every now and then as my wife has her 2015 TDI.

hotrod2448

That same procedure circulates on the BMW forums. IDK... it seems unlikely to me that:
A. Both BMW and VAG would use the same adaptation reset process.
B. Porsche would make provisions for that but, not to reset the oil service indicator without a tool.
C. Adaptation values resets are not available via the POR V2.0 or the other Porsche specific (non-PIWIS) scan tools that I've seen.

Can't hurt to try it though...

BrewDude

Why not? They use a derivative of the same engine management from Bosch...who know what else is similar.