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...

 

foot off the gas pedal is 0% tp.

 

Not in a C5 Corvette

 

Didn't think DFCO worked on the 'Vette. Thought that's what I read but I might not be remembering right.

 

No, DFCO works on Corvettes, you must be thinking of "DFCO Enable Clutch Transition", which does not work on C5s...

 

You need to look at the throttle pedal position, that should go down to 0 when you let off the gas. Actual throttle position never drops to 0 in my LS2 GTO either, but i know that DFCO works. You can see when the DFCO works by looking at the mileage calculator in the DIC or by longing injector pulse widths. The pulse widths in my car on drop to about 1.3 msec, as the PCM commands a minimum pulse width based on another table.

It is interesting to see the difference between pedal position and TPS, too. It'll make you wonder how much the car is driving itself.

 

I know DFCO is working.. I have a WideBand Sensor and can measure when DFCO kicks in... Is "throttle pedal potion" a PID??? If so, I cannot find it in the HPTuners Scanner..

My question is: how does the table mentioned in first post work... Even when DFCO is active I still see TPS of 5%...

 

There is an ETC pedal position PID under Engine->General tabs. There are also several other PIDs that have to do with throttle position. These PIDs may not be active on your car, but I have logged pedal position on mine in the past. The table in the first post works off of pedal position. If the TPS (actual position of throttle blade) went to 0, there would be a very, very small amount of air flow, as the car as no IAC. GM probalbly made the throttle stay open so that there would be a smooth transition into running again when the throttle is pressed. Also, a fully closed throttle would slow the car very rapidly.