(08-29-2025 )Rawze Wrote: Bad delete programming is a plague in the trucking industry ... Everything that Tree98 said above is correct.
(referring to CM870's only)...
(assuming you live in a country where that stuff is ok to do)...
You could have simply Taken a hammer or something to help the EGR valve to shut it fully if it was stuck partially open ... then re-installed it and leave electrical for it unplugged. -> Viola, a factory block-plate. No extra hardware needed.
The EGR temp sensor, on the intake side of the engine would also need to be unplugged. Unplugging it puts the engine in its built-in no-egr operating mode. No re-programming of anything necessary to get it there. The factory file has a no-egr operating mode built right into it. The CEL light will be on in the dash, but the engine will NOT shut down over this.
I know of plenty of people who drove their CM870's a million plus miles exactly like that with zero problems. It will have a slight boost derate in it, BUT NOT ANY POWER DERATE. The boost should/will spike to 36 or so, then drop back (due to the boost derate) to 32 psi and hold steady while climbing a steep hill. The engine will still make full power with slightly less boost, and slightly higher exhaust temps. It does not really hurt anything driving it like that.
-- SO... get that trash-can garbage engine killing delete out of it, like was already mentioned.
Put the proper factory programming back in according to the engine ser# ... and undo any other trash that you did to it that was not necessary. Fix any other engine issues it has as well while your at it.
... and after you have it back factory .. and all that is left is the CEL and boost derate.. and you have driven it like that for a while to ensure there are no other issues... then .,.. It is worth getting the boost derate removed and making the CEL light go out.
To do that, get with forum member 'running rough' if you want that done properly. He is the person who does all the old 870's around here, and his work has been reviewed on here many times by myself and others to ensure it is not harmful.
I am needing more guidance on my ECM. I am going to have to get all the hardware together to be able get running rough to be able to correct my program. I have a couple of questions.
What do I tell Cummins if I take it to them to flash back to stock?
Also if I buy a second ECM to physically send to running rough for programming so I would have a spare on the road, are all cm 870 ECMs interchangeable?
