Why the TPS reset?? - Ducati.ms

canicoll · Jul 30th, 2011, 12:01 am

Why am I reading so much about the TPS reset? What does it do/fix?
I have a stock '11 1100 SP with Termi slipons and ECU that came with the slipons. Haven't ridden it yet because i'm waiting on the paint to be finished.

Gilly · Jul 30th, 2011, 12:18 am

When an ecu is flashed or swapped out, the ecu must learn what the baseline output of the throttle position sensor is.

(I'm throwing some guesswork out here, since I am not as smart as many who do this tuning stuff blindfolded)

But anyway my understanding is that when you reset the TPS, the ecu knows that with the throttle closed, it is at certain degree of opening. Let's just say 2.8 degrees. The ecu reads the sensor voltage and assigns that to that base setting. Now the ecu can understand where the throttle when you open it up.

If the ecu was put in and not reset, it may have an erroneous baseline setting and if it is off enough, when you open the throttle, this would potentially tell the ecu you are somewhere else in the fuel map.

So in laymans terms, if you were dropped onto a piece of graphing paper "near" the starting point, and given exact directions from grid coordinate 0,0, if you were not at 0,0, those directions would put you off somewhere else. Maybe in front, behind, above or below where you should be.

The TPS Reset, establishes that location for the ecu, so when you direct the throttle opening, it delivers the proper fueling for that grid coordinate on the fuel map.

If I'm off anywhere, please correct my logic. I do like the graph paper analogy though.

canicoll · Jul 30th, 2011, 1:00 am

Understood. So this is a must or ride the bike to determine?
What should I be looking for?

Gilly · Jul 30th, 2011, 1:22 am

The 2011 bikes reset them selves each time the bike is fired up. If I recall the rule of thumb is, do not give the bike throttle during start up and it will reset the tps each time the bike is fired up. And I believe that if you do give it some juice, it will hold onto the last TPS reset from the previous startup when no throttle was applied.

I dont have a 2011, this is just what I recall from reading and you can probably find it here by searching.

Decreasing Dave · Jul 30th, 2011, 3:17 am

Quote:

Originally Posted by Gilly

When an ecu is flashed or swapped out, the ecu must learn what the baseline output of the throttle position sensor is.

(I'm throwing some guesswork out here, since I am not as smart as many who do this tuning stuff blindfolded)

But anyway my understanding is that when you reset the TPS, the ecu knows that with the throttle closed, it is at certain degree of opening. Let's just say 2.8 degrees. The ecu reads the sensor voltage and assigns that to that base setting. Now the ecu can understand where the throttle when you open it up.

If the ecu was put in and not reset, it may have an erroneous baseline setting and if it is off enough, when you open the throttle, this would potentially tell the ecu you are somewhere else in the fuel map.

So in laymans terms, if you were dropped onto a piece of graphing paper "near" the starting point, and given exact directions from grid coordinate 0,0, if you were not at 0,0, those directions would put you off somewhere else. Maybe in front, behind, above or below where you should be.
The TPS Reset, establishes that location for the ecu, so when you direct the throttle opening, it delivers the proper fueling for that grid coordinate on the fuel map.

If I'm off anywhere, please correct my logic. I do like the graph paper analogy though.

You threw me on the "graphing paper", layman's term description....

Dave

Drinky · Jul 30th, 2011, 6:59 am

Sorry don't mean to threadjack but I was wondering if doing a reset would fix my problem. My bike starts within 3 turns of the crank, really fast compared to others I've seen, however, when it starts it also shuts off within a few seconds since it can't maintain a steady idle. I have to open the throttle a bit for it to work. When it idles, it's irregular as in: goes from 1350rpm to 1050 or 1100 and then to 1200 etc. . When riding at low RPM's it's really unbearable and I have to contstantly use the clutch, and get the occasional stall at low rpm's.

So, is this a TPS thing, or a throttlebody CO and sync. problem?

bwt, 2007 bike and DP ecu with termi 2-1-2

Gilly · Jul 30th, 2011, 7:35 am

I would say that short list is what needs to be checked.
TB Sync, Idle fuel trim setting (via dealer/vdst/ducatidiag), air bleeds.

I just swapped from stock ecu to the DP 2-1-2 flash, bike fired right up, held idle. I just need to check the CO levels to make sure everything is on target.

You'll probably be very happy after you get it checked/adjusted.

freezer16801 · Jul 30th, 2011, 3:01 pm

my idle was greatly improved after a fuel trim adjustment, air bleed screws adj., and TPS reset.

This is after I installed a light flywheel. The bike starts after about 2-3 revolutions every time and idles perfect right away.

I used to get an idle that sounded like a cammed up engine and stalling issues.

Drinky · Jul 30th, 2011, 3:46 pm

so, how much does it cost usually to do TPS and fuel trim?

I called the dealers and they said max 30 mins for the TPS, didn't ask about fuel trim. And I have someone who can do the air bleed screw adjustment for real cheap( 20 euro's an hour), but he doesn't have the Ducati Diagnostics, so I have to do that at an official dealer.

Gilly · Jul 30th, 2011, 4:40 pm

Does your friend have a means to measure the CO levels?
Apart from the TPS, the TB sync, air bleeds and idle trim are probably your issue. Hard to know since you would have to know if it was set up proper at one time but fell off, or something was done and not followed up on with an adjustment, or someone adjusted it badly.

You can get a setup for doing your own TPS and Idle trim if you either purchase the VDST tuning software/cable or purchase an ODB2 cable and a Fiat 3 pin cable and download DucatiDiag from the web. If you do the DucatiDiag, it's rather simple to get up and going. Here's a link to the info I posted in the StreetFighter Forum. DucatiDiag Set Up

The link takes you in on the thread, you can back up a page or two and read more if you like.

I just finished using the DucatiDiag to Flash my stock ECU to DP 2-1-2 status, along with TPS reset, and adjusted the CO level via the idle trim. His software works dam good! I do also have a Gunsen Gastester for reading the CO, which is a must as well.