Hino 258 Rollback DPR Check Issues after computer reset

James R Grein · Oct 26, 2018

2015 258 Rollback. A little down on power. It needed other work done, so I took it to the Hino service center an hour away. They take two weeks, allegedly fix it.

Driving back to the yard, the check engine light came back on.

I pulled the codes with the same scanner I use for my Sprinter Vans, and I got a list of 29 codes, either pending, current, or permanent. I decided to clear everything out and start from scratch... to see what popped up first (since they obviously didn't clear them out). The moment I cleared the codes, DPR Check came on the screen and it was severely de-rated.

I took it back to the Hino service center (three hours away in this operational state).

Two weeks pass, and they "repaired" it, allegedly.

Driving back to the yard, the check engine light came back on again. The driver stated he could barely hit 75 on the interstate, and it started going downhill further once back in town. The next driver stated it could barely reach 45 mph in town.

I pull the codes, and I get P1515, P0299 as current, P1515, P0299 as pending, P026C Pending, and P2201 as Permanent.

I know the first two (turbo underboost and intercooler performance), and dove around inside the engine compartment, where I found evidence of a small boost leak. I cleaned up the connection at the end of the hose and tightened the clamp, hoping to clear that problem. The P2201 is permanent, and never cleared the system the last time I tried clearing the codes.

I put in a new air filter, then went to reset the computer again to see if the boost codes would go away. Ign on, not running... "clear codes." I hear a click, then the DPR CHECK warning came back on the screen and its in limp mode again. P244B appears in the computer before the engine is even started.

How can I get past this problem? Every time I clear the codes, it goes into limp mode under DPR CHECK. I don't have the Hino computer equipment, just standard OBD-II functionality from an iCarsoft MBII scanner (Chinese knockoff for Mercedes).

Today, I am going to pull the cooling stack, clean everything out and verify all the hoses and connections. I am also putting a new fuel filter in it (just standard PM time), then limping it to the International dealer in town that just got a new Hino tech on-board to see what he thinks and if we can just reset the junk and see what happens.

James R Grein · Oct 27, 2018

UPDATE:

I spent yesterday working on it most of the day. I found a degraded boost tube (intercooler to intake side) that is likely leaking, so I ordered it. I also ordered the tiny 3" boost tube from the turbo to the pipe. The pipe to intercooler on the passenger side has already been replaced.

Did you know the little 3" hose is $115!!! I expected the $140 for the large molded boost tube on the driver's side, but not so much for the tiny hose.

Anyway, most of my day was spent on replacing the passenger leaf spring. The rear bushing was worn out. I told the Hino shop about this the first time, and they replaced the Driver's side spring. Of course the popping and axle shifting didn't go away. They wouldn't sell jut the bushing, either... full leaf spring or nothing.

Other items of note:

The tech, who was obviously lost, gave us an estimate of over $15,000 to fix this truck. Items of note were a turbo, all the injectors, DPR cleaning, and the leaf spring replacement. Nowhere on the list was this boost tube, the root cause of all the problems. When nursing it to the garage yesterday morning, I listened carefully and could hear a hissing sound under hood, even in its derated state.

On Monday, I should finish the leaf spring install (I stopped early to replace the brakes on a Ram 5500 rollback when the driver reported a grinding sound and the ABS and TRAC lights on so I told him to meet me at the shop, I looked, and it was metal on one of the rears, and pretty low across the board elsewhere), then nurse it over to the International joint, where they have a tech that can allegedly do a forced regen on it and reset the computer.

This still leaves me at point A: How can I read/clear codes without setting off "DPR CHECK"?

greasytshirt · Oct 28, 2018

You need to be able to clear DPR history, which might only be possible using DX2. Check ebay for software.
Has anyone had the DPF out to check it for melting?
There's a good possibility that the injectors and dpf are likely bad. I want to know how hot the DPF got and its condition.

James R Grein · Oct 29, 2018

Allegedly the DPF was removed and inspected before this last forced regen. Hopefully the tech at Border International can clear DPR history once I finish reassembling everything today, otherwise its another case of driving it 70 miles to the nearest authorized service center and leaving it up to the 20 y/o kid who is their "trained Hino tech."

But the one question I have still... the DPR system was fine *until* I cleared the codes that appeared due to the boost leak. It was at the instant the computer reset, (engine off) that the DPR Check appeared and derate began. The computer thinks that, while the engine is off, it suddenly puked everything into the exhaust to plug it up. That is the crux of the problem. I'm going to put it together and, like any good mechanic, will clear the computer before starting the engine. If having the power disconnected for 3 days is somehow enough for the computer to stop being stupid, it will surely go haywire the moment I clear the codes for the boost leak again.