Isx unknown derate

[Papa_Buck]

Hello all

I am getting a new derate screen that I haven’t seen before so I thought I would ask the professionals here since the stealerships are useless.

The derate doesn’t specify how much derate and there are no faults or check engine codes or lights. This is a plain isx 2250 that is not demandated and not modified in any way. Dpf can replaced 2 months ago as was the egr cooler. Engine has not thrown any fault codes for a long time, until this.

Any thoughts on what caused this will be appreciated, pic of derate attached.

Thanks

[Rawze]

Insite should show you what the derate is for.

[Papa_Buck]

There are no faults in insite. Is there a way to watch the ecm logic?

[marek4792]

Have someone check the engine state monitor on Insite while going down the road, it should tell you why it's pulling air/fuel back when it derates.

[windowrattler]

Pretty sure that would be some type of scr/Def system issue with a countdown like that. It's surprising that it doesn't have some type of code though. If it was happening I would be looking at nox sensor readings/conversion, Def parameters like pump pressure, tank level and whether or not its injecting Def.

[Rawze]

maybe also post a screen shot of the regen history in Insite.

maybe the cans are getting clogged up by excess soot production due to dirty sensors??.

When is the last time you did a thourough EGR Tune-up on the enigne?
info: https://rawze.com/forums/showthread.php?...30#pid7030

[Papa_Buck]

Update problem solved


Thank you everyone for your suggestions. With the help to monitor the egr sensors, the problem resulted in the pressure sensor (which was only 3 months old) sending random values. Watching the sensor it would send random numbers all over the place. I guess that’s why the computer couldn’t decide on a derate percentage or time. I replaced the sensor and the derate instantly went away. I am still not sure why the faulty sensor didn’t generate a fault codes or cel.

Thank you everyone

[mikkhh]

What about the faulty part? Was it genuine OEM part or aftermarket garbage?