08 ud dpf problems

towmater

Seasoned Expediter
Fleet Owner
Today had a driver call saying truck has no power to climb hills. Had him drain the fuel filter as I know he was way over on lof. He said it was a lot better then about 75 miles latter check engine light came on with limp mode. Changed fuel filter (had some glitter in it) so I was thinking that was the problem. Got back on the road to the shop still in limp mode. Plugged it in thinking just had to clear the code and found a lot more wrong.

P2002. Active
P0546. Inactive
P2080. Inactive
P2002. Inactive
P2101. Inactive

So I start looking thru stuff and has a flag on for (dangerous level flag for clogging) and says to do check on dpf, so go in to start the test and says it has to stay under 16.0

So I start the test at idle it was at 0.1
It bounced around 4.5 but never went over 5.8

The codes all point to the dpf and or censors but don't know where to go with all this info.
 

Hino123

Expert Expediter
Researching
P2002 DPR malfunction
P0546 DPR inlet temp high
P2080 Abnormality of exhaust temp sensor 1 (inlet)
P2101 Intake throttle valve sticking
Looking at the info I would suspect a faulty inlet temp sensor on the Dpr, Or a broken or chaffed wire on that circuit. Inspect the sensor connector on the dpr as they are known to break right in that area. If you can monitor the sensor it should gradually rise to roughly 950-1050 degrees when during a regen. Sharp spikes indicate a faulty sensor. If replacing sensor heat it with some MAP gas and use a flare nut style wrench if possible. They seize in the DPR over time and drilling them out is no fun.
I suspect the P2002 set because of the P0546 and P2080. The temp of the dpr is used in he algorithm to determine if the regen has gotten hot enough to burn off the soot (soot burns at 752 Degrees) If it does not get hot enough, it will set the clogging risk flag you spoke of and trip a P2002.
I'm 99 percent sure you will have to reset the DPR data in order to get the derate/ CEL to go out. UD is slightly different than Hino so im not completely positive.
The P2101 Is usually either a loose butterfly shaft in the Intake throttle valve (ITV) or the wiring in the little jumper harness is compromised. Remove the CAC hose attached to the ITV. With the key off wiggle the shaft and it should have no play. If its sloppy it needs to be replaced.
Replace the fuel filter and clean out the FF housing. Then replace the filter in 100 miles or so and inspect the housing again for debris. If lots of debris is found it may be time to flush the tank.
 
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