Hino 338 DPR Auto Regen

[Maxx]

Hi Greasy,

We have a 2012 Hino 338 which is sitting at our local dealer at the moment. The problem with the truck is that it would not do auto regens. The DPR bar goes to 5 bars and asks for a regen and the engine light comes on even driving continuously on the highway for a couple of hours.

We took the truck to our local hino dealer who found code p2214 and replaced downstream nox sensor and a couple of ignitors. After replacing both of them, they called me back and said the truck would still not do auto regen. They are unable to figure out at the moment as to why this happening. They are waiting on a hino tech to come in on Monday to figure out the issue.

 

[greasytshirt]

Hi Greasy,

We have a 2012 Hino 338 which is sitting at our local dealer at the moment. The problem with the truck is that it would not do auto regens. The DPR bar goes to 5 bars and asks for a regen and the engine light comes on even driving continuously on the highway for a couple of hours.

We took the truck to our local hino dealer who found code p2214 and replaced downstream nox sensor and a couple of ignitors. After replacing both of them, they called me back and said the truck would still not do auto regen. They are unable to figure out at the moment as to why this happening. They are waiting on a hino tech to come in on Monday to figure out the issue.

Was it recently in for a engine ecu update? There was a problem with a recent update, and many trucks refused to auto regen as a result. Often the graph didn't move.

I'd have to look at what the burner is doing with DXII to give you an actual answer here.

 

[Hino123]

Would it do a manual regen if you pressed the regen button? If you pm me your vin I maybe able to look at the old Burner event log, and codes from the first time you had it in. As greasytshirt stated this is a hard symptom to diagnose without having raw data to observe. You say they replaced the downstream Nox sensor only? Is that correct? Nox sensors are usually replaced in pairs. If the part# on the Nox sensor ends in 51 is is the updated nox sensor. If you have one new Nox senso, and one old (part # ends in 50) that's when it causes an issue. The unmatched software tends to set fault codes for the nox sensors. I always recommend to replace in pairs. Another good indicator if they are old is to look at the wires and see if they have black zip ties on them. This is an indication that they are OEM installed, your truck being a 2012 the sensors have been updated after your trucks build date. I know they are $450-600 each but a tow bill is $500 and shop labor rates are 120-175hr.

 

[Maxx]

Yes it does a manual regen. I did message you the vin on the truck. The dealer today called me and told me that the burner is broken on the unit. I have asked them to hold on right now.

 

[Hino123]

I pm'ed you. Wen you say Burner is broken what exactly do they mean. Is the Mantle broken or is the Filter cracked and passing soot?

 

[Maxx]

Its the mantle that is broken.

 

[Hino123]

Yeah looking at that littered burner event log and the multiple issues it was showing its plausable for sure, we had one crack a few weeks back. I would guess its a 1-in every 400 kinda failure. I have only seen 2 personally but the other guys have seen some as well. To answer your other question about if the DPR needs to be replaced, its hard to say without having my hands on it. The temps on the report looked good. Inlet 1100, outlet 1268 ish. At those temps I would not suspect cracking or a breached DPR filter. I should note that the history of those temps is not that old. Your truck had 2 completed auto regens and maybe 28 manuals. As a generic rule, a truck should do a regen every 90-100 miles ish. So that tells me someone re-set that data within the last 2800 hundred miles or so. It may have had high temps then, so I cant completley rely on the current temps because the history is so short. If there is ANY soot on the outlet side of the dpr, its breached, and needs to be replaced, not cleaned. I also perform a "pin drop" in the back of the DPR. Insert a piece of small panio wire in the honeycomb in 13 spaced locations. If the pin will go in 7inches in all locations and no soot is present it does not need to be replaced (usually, face plugging or coolant contamination could also cause a failure but this is not your issue)
Your soot level was @ 2.3 grams, if over 5.2 grams and is a warrantable repair Hino states to replace the filter. So your good there. I do not know how many miles have passed from the data I reviewed, to the current mileage. To summarize... i see no indicators that tell me it needs to be replaced but.... without hands and eyes on it its hard to say for sure. I would suggest cleaning the tail pipe of any soot when you receive the truck back. It makes it easier to diag, as now if you see soot in the future you will now its not just old soot.
Do they want to replace the filter as well?

 

[Maxx]

No they are not replacing the filter. They are only replacing the burner. The filter was replaced at 195,000miles. There wasnt much soot in the exhaust.

 

[greasytshirt]

The mantles can be repaired, if you're brave. There is a weld on the front face of the burner, going around maybe a six inch circle. Take a plasma cutter and pierce through the weld then cut out the circle. The mantle lifts out. The broken sections can be welded back together, then the center that was cut out can be re-welded back into place.