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!
Sounds like you found your problem already.
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
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.
"You know, from Top Gun."
You watch Archer? The first few seasons are good brainless entertainment.
Well I mean Doctor Krieger is my avatar lol.
After a DEF delete?
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?
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.
Truck ran for 2 - 10 mile trips then a 200 mile round trip.
Interesting. What does your delete guy say about it?
Thanks for this info!
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.
Thanks to all who tried to help, I really appreciate it!
Thanks for the update. Glad you figured it out. I’m interested to find out if your fuel economy increases.
Glad it's running-but anytime I see the word delete-trouble.
Hi redline808 do you know what all you unplugged? If you don’t mind me asking I’m having the same problem right now
Fuel economy has not increased
FYI. That was not the fix.....Did the same thing in the next rain. Turns out water leaked onto the harness plug on the passenger side. That plug was associated with the TPS and pedal. Dried the plug and used dielectric grease on all connections. Good to go now.
Under the dash on the passenger side is a black box. That is the bulk head and all the harness connections are in there. The main harness enters from the top of the box from behind the dash. water leaks from the windshield and onto the harness, then runs down the wires and soaks the connectors. The largest connector, which is also the worst one to access is likely flooded and is causing the runaway RPM issue. I noted water also get into the TCM that is behind the plastic dash panel on the passenger side. The one that all your passengers grab onto thinking its a handle and it pulls the whole dash panel off..... I'm sure everyone has had that happen LOL. Anyways the water starts corrosion on the TCM board. Hope this helps you!
Thanks for your help I will look into it today
Do you know name for which harness it is or the the name of the large connector that you said could be soaked I’m calling around for it and I’m getting asked which harness and connector thanks for you help
I don't quite understand who your calling and for what your calling them for?
Hey guys I’ve been hunting a similar issue with my FM Hino 2004 with the 1J motor. After multiple attempts I’ve finally found my issue. The heater core had a leak and coolant was dripping on the main wiring harness connectors. The plug in the picture is for an external hand throttle for a garbage truck and it had coolant residue in the plug causing a resistance between the red and green wire making the engine rev up at idle. Hope this info helps someone