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Throttle Body?
Posted: Thu Oct 15, 2009 6:22 pm
by marv
Hi all,
A while ago, before I got my car, when I was just using this forum for research etc, I'm sure I can remember seeing a little trick whereby you can reset the throttle by doing something like hitting the brake, then the throttle pedal quickly afterwards.
Does this ring true? I've just had a trawl through the forum and can't find it anywhere!
Posted: Thu Oct 15, 2009 6:29 pm
by marv
Never mind - I found it!
nihc wrote:I have a B6 S4 Cab (2005) and have had exactly the same problem. Sometimes the performance would be mind blowing, but most of the time just so, so.
My car was origionally owned by a woman, so knowing how my wife drives the S4 ( short shifting) led me to believe that the engine adaption had cast a bad spell.
After researching the Bosch engine management system I found a little "easter egg" gem.
If you press the brake pedal ( not hard - just so the ECU knows you have pressed it) and, then immediately slip your foot off the brake and on to the throttle (full throttle) the ECU thinks you are left foot braking and switches into a racier mode. I think it must just ignore any adaption until you switch the ignition off.
Use a high gear and spend, maybe half a second touching the brake and a fraction of a second full throttle. Do it twice - just to make sure. Even the exhaust note changes. Oh, and make sure that you are using something higher than 95 RON fuel - it makes a big difference.
Regards, Chris.
Posted: Thu Oct 15, 2009 7:23 pm
by xyber
Gotta try that at the weekend!!!!
So basically, with the engine running, tap the brake and hit full throttle for a second, as if on the track left foot braking?
Posted: Fri Oct 16, 2009 9:38 am
by BlingBling
Thats right but it does not reset the throttle body. It adapts the ECU to a more aggressive driving style.
Posted: Fri Oct 16, 2009 10:57 am
by marv
Yeah, to actually reset the throttle body and/or any engine adaptation requires VAGCOM, I believe.
Posted: Fri Oct 16, 2009 11:44 am
by nihc
Hi,
The logic behind it is that if you want to balance the car with the throttle around a corner on the track you don't want the ECU to decide not the honour your "torque request" from the throttle. The way it assumes that you're track racing is by detecting that you're left foot braking.
So, rather than the ECU deciding that because of the air temp, engine load, etc it's not going to give full throttle, it does.
I'll try to hunt out the article about the Motronic that explained it.
BTW, doing a throttle body alignment with vag-com will reset adaption values, other people say differnetly, but Ross Tech and Revo insist it's the TBA that resets adaption.
Regards, Chris.
Posted: Fri Oct 16, 2009 12:22 pm
by ShaneyB
Anyone had any luck with this??
Posted: Fri Oct 16, 2009 1:22 pm
by marv
Not tried yet. Plan to test in a couple of hours when I get out of work.