BOOSTD

After 30 seconds or so the numbers seemed out of whack:

first duty cycle 14.8%
second duty cycle 84.8%

Bad TB or sensor?

Andy@Ross-Tech

The throttle body uses a pair of potentiometers to measure the angle of the throttle plate. The potentiometers are oriented opposite one another, so as the reading from one goes up, the other goes down. This is a redundancy feature in case one potentiometer fails. There is a similar pair of pots in the accelerator pedal. Anyhoo, the deal with potentiometers is you shouldn't use the very lowest or highest areas of their range. Potentiometers become inaccurate at their extrema. So, the range from closed throttle to WOT may go from 12% to 88% or something like that. I would never expect to see 0% or 100%. The two percentages don't add up to 100%. As one goes up, the other goes down. They are separate sensors. After a TBA, they usually settle somewhere around 87.5% and 12.5%.

BOOSTD

14.8%/84.8% vs. 12.5%/87.5% is a significant difference.

Andy@Ross-Tech

Bentley says 3% to 93 % is ok.

BOOSTD

thanks Andy.

Haystack

Take a look at block 117 for the calculated position of the throttle pedal, and the measured position of the throttle body. Both of these are expressed in 0-100%

The reason the adaptation results look funny is that they are the raw data from the throttle pedal position sensors. The ECU then takes this raw data and calculates where your throttle pedal is, and then uses the throttle map to calculate how open the throttle body should be at that operating point.

Take a log of 117 if you ever want to see just how different the TB postition is from the position of your foot on the pedal!