"Delayed Throttle Response"
10-16-2002, 11:28 PM
#13
AudiWorld Senior Member
Thread Starter
Join Date: Apr 2002
Posts: 1,491
Likes: 0
Received 0 Likes
on
0 Posts
More Than Just Transmission Downshift Delay
This is my second tip (previous 2.8 Avant), and my third "heavily" electronic VW/Audi auto. All have been somewhat delayed in their downshift action, which I expected after test drive and can live with. What is going on with the allroad is much more than a downshift delay.
For instance, where it really rears its evil head, is heading down a left turn lane without a signal where traffic is coming the other way. Just going from accelerator (very light...maybe 2 mph) to brake and back to accelerator, it delays. Lock the tip in 1st; still happens. I would agree that maybe it is that the bus or processor speed isn't great enough to overcome the bulk of information picked up by the sensors, but that leads me to think that the pause is related to the throttle-by-wire. There is no engine response for better than a second or two, which wouldn't happen in a typical throttle by cable. This hesitation is great when you're attempting to make a left in front of traffic...with plenty of clearance that I'd leave for a Corolla to make the same manuever... As some have suggested, my wife and I have adjusted our driving to compensate; but this is a riduculous thing to live with in a $45-50k car.
My 6 speed S4 Avant, also with throttle-by-wire, exhibits none of these traits. You can bounce up and down on the accelerator all day and its just like a throttle cable.
Which leads me to believe this is something unique to the programming on the A6 line, and most specifically allroad tips. Possibly programmed from Audi in response to soccer mom's confusing the gas and brake pedal in the previous unattended acceleration as some have suggested?? Maybe.
As far as a test drive, this problem didn't show up till living with it a few days. I've owned 3 Audi's, 1 BMW, and 4 VW's in the last ten years; all but two with automatics. None, except for the allroad, have exhibited this type of behavior; and I would certainly expect VW/Audi to have something like this ironed out well before I purchase the car.
I don't think I just whining here. I love my S4 and the allroad, which exception of what I consider to be a serious safety problem.
For instance, where it really rears its evil head, is heading down a left turn lane without a signal where traffic is coming the other way. Just going from accelerator (very light...maybe 2 mph) to brake and back to accelerator, it delays. Lock the tip in 1st; still happens. I would agree that maybe it is that the bus or processor speed isn't great enough to overcome the bulk of information picked up by the sensors, but that leads me to think that the pause is related to the throttle-by-wire. There is no engine response for better than a second or two, which wouldn't happen in a typical throttle by cable. This hesitation is great when you're attempting to make a left in front of traffic...with plenty of clearance that I'd leave for a Corolla to make the same manuever... As some have suggested, my wife and I have adjusted our driving to compensate; but this is a riduculous thing to live with in a $45-50k car.
My 6 speed S4 Avant, also with throttle-by-wire, exhibits none of these traits. You can bounce up and down on the accelerator all day and its just like a throttle cable.
Which leads me to believe this is something unique to the programming on the A6 line, and most specifically allroad tips. Possibly programmed from Audi in response to soccer mom's confusing the gas and brake pedal in the previous unattended acceleration as some have suggested?? Maybe.
As far as a test drive, this problem didn't show up till living with it a few days. I've owned 3 Audi's, 1 BMW, and 4 VW's in the last ten years; all but two with automatics. None, except for the allroad, have exhibited this type of behavior; and I would certainly expect VW/Audi to have something like this ironed out well before I purchase the car.
I don't think I just whining here. I love my S4 and the allroad, which exception of what I consider to be a serious safety problem.
10-17-2002, 04:55 AM
#15
Junior Member
Join Date: Mar 2000
Posts: 1,605
Likes: 0
Received 0 Likes
on
0 Posts
My friend bought a Passat a few months ago and is complaining of the same thing.
Maybe check on vwvortex.com to see if those guys are having problems too...you know power with masses or something like that!
10-17-2002, 06:57 AM
#16
Junior Member
Join Date: Aug 2002
Posts: 718
Likes: 0
Received 0 Likes
on
0 Posts
Re: "Delayed Throttle Response"
I have a 2001 VW Gti VR6 (5 speed/DBW) that exhibited simular traits to our allroads though not as dramatic.
Everyone seemed to know about this issue in the VW performance market. When I chipped my car I was told one of the performance enhancments was the reduction of DBW delay.
Well since the GIAC chip was installed it now feels like the throttle is connected directly to the throttle bodies. No delay.
My point is that if this was acomplished on my Gti why not on chipped allroads? I understand and recognize the difference in TIP lag (another issue) but just like DBW lag a software change should take care of it.
Any thoughts ?
Robert
TrackJunkie.Com
Everyone seemed to know about this issue in the VW performance market. When I chipped my car I was told one of the performance enhancments was the reduction of DBW delay.
Well since the GIAC chip was installed it now feels like the throttle is connected directly to the throttle bodies. No delay.
My point is that if this was acomplished on my Gti why not on chipped allroads? I understand and recognize the difference in TIP lag (another issue) but just like DBW lag a software change should take care of it.
Any thoughts ?
Robert
TrackJunkie.Com
10-17-2002, 07:22 AM
#17
AudiWorld Super User
Join Date: May 2002
Posts: 3,833
Likes: 0
Received 0 Likes
on
0 Posts
Absolutely! It's all software...
There is no delay introduced by the "wire" in Drive-By-Wire, and processor speeds are plenty fast. (Non drive by wire fuel injected systems still have electronics + a throttle cable. All that's been done is to eliminate the throttle cable. I've seen engine management systems using Motorola 68K chips, which are ancient, as that's all that's needed.)
The allroad's software has been altered to change the car's throttle response. The first tiptronics were criticized for overly abrupt off the line performance by the press. Now, they complain of the opposite.
If people want something to be done, talking with APR, GIAC, etc, might be a better route to take.
The allroad's software has been altered to change the car's throttle response. The first tiptronics were criticized for overly abrupt off the line performance by the press. Now, they complain of the opposite.
If people want something to be done, talking with APR, GIAC, etc, might be a better route to take.
10-17-2002, 08:33 AM
#18
New Member
Join Date: Jul 2001
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
Avoiding an accident is as much a function of acceleration as braking
...it's often why we purchase a more powerful engine and Audi has to understand that delayed throttle response IS a safety issue!
I've personally just barely avoided 3 separate intersection accidents and 2 freeway wrecks because of this inconsistent lag in acceleration.
I really believe that Audi/VW is over reacting to the "sudden acceleration" ghost of the past and could cause the same branding failure they experience before by continuing to delay an important and positive response to this issue.
I've personally just barely avoided 3 separate intersection accidents and 2 freeway wrecks because of this inconsistent lag in acceleration.
I really believe that Audi/VW is over reacting to the "sudden acceleration" ghost of the past and could cause the same branding failure they experience before by continuing to delay an important and positive response to this issue.
10-17-2002, 08:41 AM
#19
AudiWorld Senior Member
Join Date: Oct 2002
Posts: 1,179
Likes: 0
Received 0 Likes
on
0 Posts
Re: More Than Just Transmission Downshift Delay
I have also noticed this mostly after using the brakes. We were told by VW that when the brake is pressed the computer prevents full throttle. I suspect that Audi is doing the same since they had a minor problem with driver error a few years ago. So is there a delay from the time the brake is used until the throttle responds? I am sure that this is some type of programming issue. It's also very inconsistent and I haven't been in any situations where I feel it could cause an accident. The hesitation is very short and just somewhat startling when it occurs. The vast majority of time everything is fine. I'm starting to use sport mode more often only due to the more aggressive shifting.
10-17-2002, 05:45 PM
#20
No delays with 2003 Tip
I've noticed that I don't have a delayed response when I'm using the Tiptronic mode. The auto tranny has a split second delay when you go full on the gas. However, I'm learning to apply right timing on putting enough pressure on the gas pedal when on auto mode just before going full on the pedal. This sort of eliminate the delay. Just my 2 cents.