Cm2250 derate

[Aleeex]

I’m usually pretty decent at figuring things out.. but I’m stumped. (Maybe I’ll find my missing mpg after this)


No codes

De mandated , rawze program


I started noticing boost limiting at 25-29 psi

Kinda thought maybe high elevations.. maybe the 100+ degree weather..


Datalog with insite while driving, “engine state - automotive governor” and when giving it full throttle “torque limiting” truck feels lazy


Within the last couple months , not in any particular order
Last week pm done with all new filters including fuel.
New imap
New exhaust gas pressure sensor
Fuel actuator
High pressure relief valve



I might be forgetting something… I did my air filter a few months ago… maybe that’s clogged?

What else can I check or pay attention to on the datalog to try and figure out why it’s de-rating

[windowrattler]

There are some really convincing black market sensors floating all around. My cummins rep couldn't even tell the difference. These knock off sensors can be totally out of whack and cause issues. As an example one of the black market back pressure sensors would read like 30 psi with the truck off. Something to consider and take a closer look at.

[Aleeex]

All sensors came directly from Cummins

[Rawze]

Pull the down-pipe away from the first exhaust can and see if it picks up power/boost on a test drive. Maybe the exhaust is clogging up?.

you can also make you a screen file in CT to see what might be holding it back. The CBL_fuel_State being the most important setting to monitor, along with a few other power related settings ...
ref: http://rawze.com/forums/showthread.php?t...3#pid58693

[Aleeex]

(07-18-2023 )Rawze Wrote:  Pull the down-pipe away from the first exhaust can and see if it picks up power/boost on a test drive. Maybe the exhaust is clogging up?.

you can also make you a screen file in CT to see what might be holding it back. The CBL_fuel_State being the most important setting to monitor, along with a few other power related settings ...
ref: http://rawze.com/forums/showthread.php?t...3#pid58693

I have no cans, which brings me to next question. Where are the terminating resistors located?

Maybe my muffler is collapsing? Can the factory flex pipe implode?

I’ll do an ohm test on the weatherproof connector when I stop.

[Rawze]

Just because you have no DPF cans, does not mean the exhaust (or intake) cannot get restricted. I have found animal remains in exhaust pipes before, .. I have found the DEF doser seeping, and clogging up de-comp tubes before, and all sorts of things that would clog up the exhaust of a vehicle over the years. Even saw a straight piped Pete 389 once that had a bunch of sticks and leaves in the elbow at the bottom of the stack on the drivers side, all burnt to ashes and making a brick in there. How it all got down in there is anyone's guess. - Assumptions are the mother of all overlooked problems when it comes to mechanical things.

[Rawze]

(07-18-2023 )Aleeex Wrote:  I have no cans, which brings me to next question. Where are the terminating resistors located?

One is located inside the turbo actuator itself. The other is located down at the DFP cans at one of the controllers. - If some idiot unplugged the controllers down there or the pig-tail to the after-treatment system, then that is good cause for one of the terminating resistors to be missing, and is a common mistake that these clowns that do these deletes do.

You mentioned that it has muffler, so I can only assume that some clueless fool also removed the whole system under there, unplugging everything, not knowing any da$mn better.

[Aleeex]

I guess I have somewhat of a game plan.

Monitor engine with CT.

Get a new air filter and drop the exhaust to check everything. It’s not that difficult to do on my truck.


Hope I figure this out

[Aleeex]

I could not get CT set up…

But in insite I did manage to catch it say “air fuel control derate” under acceleration


Inactive code appeared. Turbo inlet air temp sensor