2015 Hino 258 RPM run away

[redline808]

Okay, I have a problem with my 2015 Hino 258 rollback tow truck. Issue started yesterday. When I start up the truck after about a minute of idle the engine RPM instantly goes to 3000, no way of stopping it, I just need to turn the key off. It only does this when in neutral. Another example is I'm driving, I'll come to a stop and almost right after I shift into neutral the RPM runs away. It does not matter if the parking brake is on or off. Note; a few days before the issue started, I had the DEF system deleted. I scanned the truck and I get a P1133 Malfunction of operational accelerator sensor (high)

Anyone ever have this problem? any advise. There is no dealer in my area.

Thanks!

 

[Truck Shop]

Sounds like you found your problem already.

 

[redline808]

I'm wondering if anybody has had this happen to them because of a faulty accelerator pedal assembly? I'd hate to change of $500 pedal and that not fix the problem

 

[Coaldust]

That’s rare to have a pedal position sensor fail like that. They have a idle verification feature that’s supposed to prevent that. I would call your dealer or contact Hino directly and see if there is a recall or at least a TSB or something available regarding the issue. That’s a serious safety concern.

 

[Coaldust]

 

[92U 3406]

View attachment 271263

"You know, from Top Gun."

 

[Coaldust]

You watch Archer? The first few seasons are good brainless entertainment.

 

[92U 3406]

You watch Archer? The first few seasons are good brainless entertainment.

Well I mean Doctor Krieger is my avatar lol.

 

[Truck Shop]

I would call your dealer or contact Hino directly

After a DEF delete?

 

[Coaldust]

I suppose the delete could be related. Good point.

It could just be a coincidence. How many hours did it run after the delete before it started idling weird?

 

[Coaldust]

A quick duck duck go search for “Hino 258 high idle” results in numerous reports of what the OP describes. Wiring harness corrosion near the fuse box is a common theme.

 

[redline808]

I suppose the delete could be related. Good point.

It could just be a coincidence. How many hours did it run after the delete before it started idling weird?

Truck ran for 2 - 10 mile trips then a 200 mile round trip.

 

[Coaldust]

Interesting. What does your delete guy say about it?

 

[redline808]

A quick duck duck go search for “Hino 258 high idle” results in numerous reports of what the OP describes. Wiring harness corrosion near the fuse box is a common theme.

Thanks for this info!

 

[redline808]

Interesting. What does your delete guy say about it?

Originally they said just unplug the EGR and the DEF pump. They were probably assuming that all the associated equipment had been removed as most do.... But it was all left in place and a new exhaust was routed around it. That being said, they said to unplug everything associated with the deleted equipment. I did and just did a 200 mile trip without issue. Seems that a sensor was feeding information back to the ecu and the ecu didn't know how to handle it.

 

[redline808]

Thanks to all who tried to help, I really appreciate it!

 

[Coaldust]

Thanks for the update. Glad you figured it out. I’m interested to find out if your fuel economy increases.

 

[Truck Shop]

Glad it's running-but anytime I see the word delete-trouble.

 

[MikeMike258]

Originally they said just unplug the EGR and the DEF pump. They were probably assuming that all the associated equipment had been removed as most do.... But it was all left in place and a new exhaust was routed around it. That being said, they said to unplug everything associated with the deleted equipment. I did and just did a 200 mile trip without issue. Seems that a sensor was feeding information back to the ecu and the ecu didn't know how to handle it.

Hi redline808 do you know what all you unplugged? If you don’t mind me asking I’m having the same problem right now

 

[redline808]

Thanks for the update. Glad you figured it out. I’m interested to find out if your fuel economy increases.

Fuel economy has not increased