DFCO minimum TPS% ???

[SideStep]

I must not be reading this right???


"DFCO Enable TPS vs. RPM: Throttle position must be below this table value"

(See attached pic.)

The way I read this, the TPS must be below these values (at given rpm) in order to enter DFCO..., right???

My TPS is never this low, how is this working???

Any help appreciated...

[WS6FirebirdTA00]

depends how it will reference the TPS. I am not totally sure on the vettes, but I thought that idle TPS is "0%" for lookup tables. I could be totally wrong though.

[Dirty Howie]

Maybe referrencing one of the Vette tunes in the Repository will help you....I'm curious how this works myself.


DH

[alanderson1978]

I don't know why yours is so low. Attached is the stock table from my truck. You do have to be below this table to enter DFCO. have you checked that are actually entering DFCO? You would see your inj PW go to about 0.1 ms when you are. When I was tuning mine, the easiest way for me was to log TPS%, inj PW, main spark advance, speed, RPM, and MAP in chart display.

[SideStep]

depends how it will reference the TPS. I am not totally sure on the vettes, but I thought that idle TPS is "0%" for lookup tables. I could be totally wrong though.

I have never seen less than 5% TPS, idle or decelerating...

Maybe referrencing one of the Vette tunes in the Repository will help you....I'm curious how this works myself.


DH

This is this table has not been touched and I have compared it to other 2001, 2002, 2003, 2004 C5 stock tunes.... they all have the same data in this table

I don't know why yours is so low. Attached is the stock table from my truck. You do have to be below this table to enter DFCO. have you checked that are actually entering DFCO? You would see your inj PW go to about 0.1 ms when you are. When I was tuning mine, the easiest way for me was to log TPS%, inj PW, main spark advance, speed, RPM, and MAP in chart display.

Corvettes have "throttle by wire" Electronic Throttle Control (ETC)...
I know DFCO is working I can monitor it with my wideband. It (DFCO) comes on exactly when it should. I just do not understand how this table realates to the process...

[alanderson1978]

Maybe you just got an extra table....
Some call it a bug, some call it a feature....
They had some extra room in the PCM and they had to put something there....

Try setting it all to 0 and see if it still works.

[WS6FirebirdTA00]

I know the normal PID for TPS will never read zero, but I thought on the ETC cars there is another PID which will go by the actual TPS that YOU give, not what the idle commands. Like I said though, I am not too familiar with their operation.

[2000C-5]

I wondered about this myself, but just wrote it off because I could change it like I wanted without using this table. I attached my table, which is a little different since it's on a 2000. I changed the other two to get the DFCO to come on a little earlier. I was barely seeing DFCO in 6th gear before this. Also, on the last tank of fuel, I had one tune session and quite a bit of spirited driving and my average mpg was 19.8.

[Dirty Howie]

For what is worth my TPS is 8 at idle which is 750 rpm..............


DH

[EC_Tune]

The TPS % used to determine shift points isn't one of our "standard" PID's. It's a combo of APP sensor position, ETC%, and ETC%-Idle ETC%.

Chris had a post about that. Couldn't find it tonite: tired... <yawns>

[Dirty Howie]

The TPS % used to determine shift points isn't one of our "standard" PID's. It's a combo of APP sensor position, ETC%, and ETC%-Idle ETC%.

Chris had a post about that. Couldn't find it tonite: tired... <yawns>

So I am confused.

When I am sitting at idle and my TPS% is showing 8 at 750 rpm ............
.......isn't that 8% of the max throttle position?

And what is APP......please??


DH

[EC_Tune]

Accellerator Pedal Position.

[Dirty Howie]

Accellerator Pedal Position.

OKAY...thanks!!!


DH

[EC_Tune]

The 8% is just how much throttle is necessary to keep the engine running. To determine DFCO TPS% is a couple additions/subtractions from the idle TPS% to find the *0* point.