Yeah, my '01 had the ECO and it worked well - But it was a gasser, Anybody remember the 'economy' gauges for cars? They were nothing more than manifold vacuum gauges (or manifold pressure - Like Brother Dave said, 'nothing is the absence of something..."). The best economy came when the throttle plate was closed and vacuum was highest. Of course there is no throttle plate on a diesel and manifold pressure is basically ambient air pressure when there is no boost.
But while we're flaming the overhead, I really miss the compass option that would display the degree heading instead of just the major compass points. It was elegant. And this is improvement?? I've had this truck four months and I'm finding a load of stuff that was better in my '01. Disgusting. Change, not for the better!

 

I've had the scan gauge for a while now. Works great. You have to adjust it to get the average right for each vehicle you put it on. Yes it works on any 94+ Vehicle. I've used it on multiple vehicles my self. Also scans for codes and will let you clear them. Case in point my brothers 02 had problems put the SG on his truck and sure enough lift pump dead.
I was dynoing my 05 and forgot to plug the IAT back in and limp mode, scaned and found the code and cleared it in about 30sec.

 

Ok,
Glad we cleared up the fact that the older trucks had the instant economy readout. I just found this thread:

Has anyone tried putting an older trip computer in a newer truck? I don't think it will work without programming the computer to pass along this info to the overhead. It might work; but, I would not spend much money on trying.

Dan

 

[QUOTE=Herrin811;891649]Short short answer...No, you cant have it

Short answer: The instant eco is only available on gas enginesQUOTE]

My brother's 02 Dodge diesel had. I bet most of the guys with 2nd gen trucks have this option. I really like knowing the instant fuel mileage. Wish my 03 had this feature.

 

I actually recently attempted installing an '05 1500 overhead trip computer in my '06 2500, mainly because I wanted to add the homelink feature. No luck!

When I first hooked it up it appeared to start working and then just went to a blank screen. I then tried the service manuals' self diagnostics test, but nothing happened. I'm not sure if it was the overhead computer itself or that the ovehead computer couldn't communicate with the ECM.

Another issue during installation was that the switch made my electronics go haywire. The headlights came on, the CD changer started cycling endlessly and the truck wouldn't start. I replaced the overhead computer with the original unit and everything went back to normal. The switch also set a few codes, including a fuel issue and two others that weren't identified by the Smarty. I was able to clear them all and haven't had a problem since then.

Finally, while researching the idea of replacing the overhead computer to add the homelink function I learned that the '05-'06 overhead computers supposedly have different wiring/connectors then the earlier versions, so the idea of adding an earlier version overhead computer probably wouldn't work.

Hope this helps.