2006 Hino 268 no power uphill

davidw787

Rookie Expediter
Owner/Operator
Hey guys my truck is loosing power uphill dropping as low as 25 mph then sometimes it’ll cruise right up the hill. No lights on dash but an occasional check engine light. The codes I’m getting are p0218 and p0876, anybody have this issue?
 

natsys

Seasoned Expediter
Owner/Operator
Is the ABS light on? Those seem to be transmission trouble codes--fluid too hot maybe? I never had those codes but it doesn't sound good. Does the tach wind out when the power drops? If it does your transmission may be slipping. I wouldn't wait too long to get that corrected.
 

davidw787

Rookie Expediter
Owner/Operator
Hey so I figured it out, I changed out the nsbu switch and a new transmission filter and fluid and she’s running back to normal going up hills with no problems
 
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Alex2

New Recruit
Owner/Operator
Hey so I figured it out, I changed out the nsbu switch and a new transmission filter and fluid and she’s running back to normal going up hills with no problems
I'm having the same issue with my Hino 338, loosing power uphill, I replace the transmission about two weeks ago, with a remanufactured transmission also it has a new rad.
 
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greasytshirt

Moderator
Staff member
Mechanic
Hi Alex2. Are there any warning lights on? Have you had the truck checked for codes? There are countless reasons for low power.
To access engine, DCU, BCU, VCS codes, an appropriate scan tool must be connected to the 16 pin connector. Not all scan tools work on Hino engines. To access codes in the transmission and ABS, connect to the 9 pin connector. More generic code readers will work on these systems.
 

Alex2

New Recruit
Owner/Operator
Hi Alex2. Are there any warning lights on? Have you had the truck checked for codes? There are countless reasons for low power.
To access engine, DCU, BCU, VCS codes, an appropriate scan tool must be connected to the 16 pin connector. Not all scan tools work on Hino engines. To access codes in the transmission and ABS, connect to the 9 pin connector. More generic code readers will work on these systems.
yes, transmission was overheating took truck to a Hino dealer for a diagnostic paid 1k to get this done. At that time ABS light was on. they told me to replace the rad, I did replace the rad, find out that the Abs sensor was dirty, clean it it light went away. transmission its not longer overheating but now it loses power uphill. and the rpm gets stuck at 15000 rpm and it suddenly jumps back and forth to 2000 rpm but only going uphill.
 

greasytshirt

Moderator
Staff member
Mechanic
There is a definite link between the ABS light and transmission failure. When the ABS light is on , the torque converter unlocks. An unintended consequence was the fluid got much hotter and it overwhelms the trans cooler.

I've looked at the circuit on a wiring diagram and found the one wire to cut to prevent the TCM from seeing ABS light input. So now if the ABS light comes on, it's not going to risk damaging the transmission

Hino fixed this in 2017, I think. Possibly 2015.

Have you had it re-scanned since this new problem developed? When they replaced the trans, they're supposed to reset the shift adaptions in the TCM. Do you know if this was done? The TCM has learned the characteristics of the old transmission, so if you stick a new trans in and don't reset it, that can cause issues.

They likely wanted to replace the radiator because when a trans grenades the shrapnel ends up in the trans cooler. You can destroy a new transmission when debris makes it through the cooler.
 

Alex2

New Recruit
Owner/Operator
shift adaptions was reset at the the dealer.
however radiator started leaking today and I opened the rad to find out that transmission fluid is mixed with coolant. is this a rad failure or the transmission going bad ?
 

greasytshirt

Moderator
Staff member
Mechanic
It's a radiator failure, but if coolant has made it into the transmission fluid that's a big issue.
 

greasytshirt

Moderator
Staff member
Mechanic
If transmission fluid is in the coolant it can only come from the transmission cooler inside the radiator., or someone poured it into the radiator.
 
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greasytshirt

Moderator
Staff member
Mechanic
On Hinos, it's almost always always combustion gases in the coolant, or external leakage. They rarely mix fluids.

If you're getting transmission fluid into the coolant, then it's coming from the transmission cooler inside the lower tank of the radiator.
 

Alex2

New Recruit
Owner/Operator
I replaced the radiator already, but this morning I noticed that it was leaking from the hose that goes down from the reservoir tank,
I opened the rad cap while the truck was on and it released a lot of pressure and the stop the leaking immediately.
 

greasytshirt

Moderator
Staff member
Mechanic
With the truck cooled off some, take off the cap and start the engine. Are bubbles coming out of the radiator neck?
 

Alex2

New Recruit
Owner/Operator
Does anyone know what this means?
I was driving for about 20 minutes, went to the yard and I turned the engine off to check the coolant level on the radiator. When I turned the truck back on this came on. It did let me move the truck for a little bit and then the display when off. IMG_2931.jpeg
 

greasytshirt

Moderator
Staff member
Mechanic
Have you driven through rain recently? Water can get in the firewall junction box behind the engine air filter and cause communication errors with the transmission.
 

Alex2

New Recruit
Owner/Operator
Have you driven through rain recently? Water can get in the firewall junction box behind the engine air filter and cause communication errors with the transmission.

well, I went thru a wheel wash today similar to the one on the picture. been thru that wheel several times tho. Appreciate your time Man. Ever since I bought that truck is been nothing but nightmares. 1727921604315.png
 
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