CM 871 Code 2639, DPF won't clean

[Doops22]

Sitting at an idle at first startup was 0.35psi and after a 5 mile drive showed peak delta p of 0.74

[Rawze]

(03-08-2019 )Doops22 Wrote:  The filters were cleaned and baked. Is that high enough to trip the light? Maybe the DPF delta P sensor is bad?

don't forget that the crossover tubes for the DPF Delta-p can get partially clogged and make it read high too. Also it can read wrong if the rubber bushings at its feed-point get cracked/leaky.

Lastly, if you had the DPF and DOC baked out, you need to perform a "DPF Maint. Reset" or whatever its called in Insite.

[Doops22]

I blew the tubes out with shop air while it was apart and I put new rubbers where the steel tubes meet the sensor.

I didn’t know about the reset on insite I guess I’ll have to find someone to do that.

[DosGatos]

Curious which test strips you have

[Unilevers]

.75 psi is like 1.5 inhg. Well not obscenely high that is more than i would like on cleaned filters.

It is not enough to trip the light yet, but hopefully it doesnt go up more.

[Doops22]

The test strips I used were Fleetguard CC2602. I attached the test from quickserve.

Uni: thanks for the info. I’ve made an appointment Monday at a local Cummins dealer to have them plug in with insite and do the DPF reset and check things out. I don’t think I can do much more without a laptop unfortunately.

[Doops22]

Quick update I took it to a shop that could plug into it, unfortunately I wasn’t able to take it down. They weren’t able to get the light out but on the way home it went out and hasn’t come back on. Thanks for the help!

[Marajin]

easy to clean dpf. use drill + chisel on doc,dpf,scr can too. re-program ecm and finally go make money with truck. :big_smile: