EGR Valve Position/Dashdaq

[sjl2725]

I have some questions about the EGR position. I have one of my monitored parameters on the Dashdaq set for EGR_ERR. its range is -100 to 99. Does anyone know (1) is that reading the feedback from the position sensor or is that the number the computer is telling the valve to get to. In process control terms, is that the measurement or the setpoint? (2) Is "99" open or closed?

I run the 250 tune because for one, I can't afford any bigger tunes and I really don't think I need them for a daily driving. I read or asked before if the 250 tune closes the EGR valve and it was my understanding that it was closed under acceleration. It seems that I can be driving down the highway and sometimes it reads -100 and sometimes it reads 99. I'm also not sure what the system control bases its status off of, temperature? particulates? Regardless of what it measures, I can't find any pattern to its position. Maybe there's an electronic glitch somewhere in the measurement or the monitoring. Sometimes it seems to pop open and then shut right away.

Perhaps I should make a recording and analyze the numbers. (?)

(did that all make sense?)

[08stroker250]

You need to monitor the % parameter. It will show you the % that the valve is open. I think its EGR Position or something like that.

[dieselkane]

Commanded EGR % is the one you want to watch.

[sjl2725]

OK. Thanks guys... Not sure why I never used that one... So "commanded" will mean "setpoint" or what the computer is asking the valve to open to, correct? So that makes me wonder what the valve is actually opening closing to. If the control says "go to 45% open", can I see the feedback saying "ok, I'm at 45%"?

I should just block the dang thing off and be done with it, eh?

[08stroker250]

Originally Posted by dieselkane

Commanded EGR % is the one you want to watch.

That's the one!

My valve hasn't been functional in over a year, so I couldn't remember what the parameter was.

Originally Posted by sjl2725

OK. Thanks guys... Not sure why I never used that one... So "commanded" will mean "setpoint" or what the computer is asking the valve to open to, correct? So that makes me wonder what the valve is actually opening closing to. If the control says "go to 45% open", can I see the feedback saying "ok, I'm at 45%"?

I should just block the dang thing off and be done with it, eh?

The Commanded EGR parameter is going to show you exactly what the valve is doing using a 0% to 100% basis, with 0% being closed and 100% being fully open. You won't, and shouldn't see the valve cycle with the 250 tune unless the truck is idling. The 210 tune is the same way. The 175 and lower tunes will cycle it all the time. The 275, 310 (and 300), and the 350 tunes will never cycle the valve, even at idle you won't see it cycle.

[sjl2725]

Crystal Clear.

Changed it on the way home from work and everything's as you explained.