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Wesoja2

So a little back story, about 6 months ago I attempted to demandate the egr and after several attempts of getting the programming right we were never successful so I just replaced egr valve and moved on. We flashed ECM to a stock file not the correct file for my engine serial but one that seemed compatible and was a higher horse. After a month or so of that and it just not feeling it was running right I pulled ECM and took it down to dealership and had it flashed to correct file to engine serial number but again it just hasn’t seemed like it runs the way it used to. Sometimes it runs flawless and other times it seems to lag or build lots of heat. I replaced every sensor related to intake exhaust and egr including a new turbo and controller. We’ve tested injectors also. Recently I did a couple data logs with insite and came across the ambient outside temp reading in the ECM reads a consistent 72 degrees 5.17 volts. All the time never changes. The dash temp reads correctly though and there’s no faults. I checked quickserve and went to dealership to check oem side and both say the dash and ECM share the same temp sensor in the drivers mirror. My question is that is there something that could’ve got manipulated in the cecu to block the ECM from getting live readings from the sensor? That’s the only thing I can come up with but have to no way to confirm it and would flashing it to stock file by vin and serial number with ECM in truck fix that issue? It’s a Cm870 500hp 2007 T800 build date 07/06. I know the ECM uses that temp for base parameters so I think it’s the root cause of it running terribly when it’s not within close proximity of 72 degrees

Rawze

It could have lost the address to the OEM temp sensor?.

and as far as de-mandate goes.. forum member 'running rough' is the person who does the older CM870- stuffs, and is officially approved. - CM870's can be very quirky to get right.

Wesoja2

I never thought of that.. I wonder if dealership flashing stock file again with ECM in the truck would restore that address or not.

Yeah I found out how quirky they can be. Hopefully he’ll chime in and have an idea of what it can be. I’ve scoured your site and others and have yet to find anyone with this issue. Plenty of 870 demandate issues but this one seems to be unique