P0087 and U1123

curiousmario · May 29, 2023

Good afternoon everyone

I'm having issues with a 2010 Hino 268 loosing power. After a few minutes check engine light with come up and truck limited to 2500rpm and 50mph on flat. Once I start going up hill (even empty) it won't go above 25mph.

So far I have replaced fuel filter, checked the filter housing for debris, checked the fuel lines all the way from tank to pump and pump to common rail. Disassembled the common rail to see if there was any obstruction and there is not.

Only noticed that there is a valve on the common rail (I think is the pressure release valve that leads to a fuel return line) that it's throwing huge amounts of fuel. I don't know if that is the way it's supposed to be, just wanted to mention it as I'm not familiar with it.

I'm thinking the actual pump or injector. What do you think?

curiousmario · Jun 2, 2023

Fuel pump replaced and code went away BUT thus truck is not giving me a break it looks like that was not the issue with loosing power.

I still have code U1123 and truck goes into limo mode, not going over 50mph revs not going over 1700rpm. So far we have checked the grounds, batteries, actuator (turbo was recently replaced)

greasytshirt · Jun 3, 2023

U1123 is an error on the proprietary CAN between the turbo's VNT controller, the EGR valve and the ECU.

curiousmario · Jun 6, 2023

greasytshirt said:
U1123 is an error on the proprietary CAN between the turbo's VNT controller, the EGR valve and the ECU.

Thanks for the info. I'll be checking on it tomorrow, but this truck had a delete when I bought it, so EGR shouldn't be there, right?

Would you think is possible something related on the delete? Although that code was not there before replacing the turbo

greasytshirt · Jun 6, 2023

Deletes are so hit and miss. It's really hard to say.
If you unplug the EGR , does it set EGR codes?

If I'm not mistaken, there's a short section of harness between the VNT and the main harness. Make sure both ends are securely attached.

curiousmario · Jun 10, 2023

greasytshirt said:
Deletes are so hit and miss. It's really hard to say.
If you unplug the EGR , does it set EGR codes?

If I'm not mistaken, there's a short section of harness between the VNT and the main harness. Make sure both ends are securely attached.

Yesterday I was playing around with it and probably not the best idea but I was suspecting that the new turbo had issues, sooo I disconnected the actuator from the new turbo (didn't remove it just unplugged it) and connected it to the old turbo (just bringing the old turbo close enough to be able to plug it). The damn code went away! So now I know is the stupid actuator. Do new turbos need to be calibrated? (Ok ok don't kill me for that question, I'm a Rockie just trying to learn)

Can you replace just the actuator on these turbos? The old turbo was leaking oil but the actuator seems to be fine, can I just swap actuator from old turbo to the new one?

danthewolf00 · Jun 10, 2023

With most newer trucks yes they have to be calibrated......just about every part has to be now a days.

greasytshirt · Jun 13, 2023

It's calibrated at the factory. I know it sucks, but I'd remove and return it.

curiousmario · Jun 14, 2023

greasytshirt said:
It's calibrated at the factory. I know it sucks, but I'd remove and return it.

I'm really thinking on buying the DX3 and the PTT ( I own hino and UD), BUT! would just any OBD2-USB adapter work or is there an special one I need to use for the software to work? (I have 9 pin to OBD2 adapter)

greasytshirt · Jun 14, 2023

A Nexiq USB-Link 2 is the recommended interface tool. This also works with a wide array of different diagnosis programs, like Isuzu IDSS, Allison DOC, Cummins Insite, Wabco, and probably many others that I don't have any experience with.

curiousmario · Jul 7, 2023

greasytshirt said:
A Nexiq USB-Link 2 is the recommended interface tool. This also works with a wide array of different diagnosis programs, like Isuzu IDSS, Allison DOC, Cummins Insite, Wabco, and probably many others that I don't have any experience with.

Thanks I just ordered. Forgot to mention that exchanging the old actuator to the new turbo worked. I guess the new actuator was bad from factory but the truck is running fine now