P1459,P2202, p2215

rgf451

Seasoned Expediter
Owner/Operator
What are the chances of both NOx sensors failing at the same time? P1459 is an egr code, could a bad egr valve cause a false reading for the NOx sensors? This is on a 2013 Hino 258. Forgot to add that.
 
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greasytshirt

Moderator
Staff member
Mechanic
What are the part numbers of the NOx sensors? Check them both. The latest ones have part numbers ending in 540.

It's possible to have a harness problem that takes them both out. You'll have to check each connector for 12v, ground, CANH and CANL. You will set codes doing this. You probably need an actual diagnosis at this point.

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rgf451

Seasoned Expediter
Owner/Operator
The are not ending in 540. I replaced both sensors in January of 2017 on this truck. I'll check for power, ground etc. at them. What about the egr code P1459? Can the egr valves be cleaned on these trucks? According to the manual on this code, its basically check wiring and replace egr valve. Is that a common replacement? I hesitate to just do it since the local dealer is quoting me $2500 for the part. Most of my problems with these trucks have all been burner maintenance issues that threads on this forum have been so helpful with. I do have the hino diag software, if there are any values I should look for with it to help diagnosis? I appreciate all your help.
 
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greasytshirt

Moderator
Staff member
Mechanic
Yes, you can clean them. Can you cycle it with the software? If the valve has power, ground, and normal CAN voltages, and you can't cycle it, it's probably bad.

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greasytshirt

Moderator
Staff member
Mechanic
I would check the junction box under the air filter for water intrusion. There's very likely to be a small gap in the cover insulation. Water gets past the gap and can cause widespread corrosion. A new cover comes with a better seal and an improved harness support. There's a wire repair kit available to replace connector terminals. You may also need a terminal release tool kit.

Is this your problem? I don't know, but there's a chance.

I would voltage drop test the power and ground circuits at the EGR valve, and also confirm proper CANH and CANL voltage (roughly 2.6 and 2.4 volts).
There's also a temp sensor in the valve that can fail, so even if the valve will move, it still may require replacement.

Does everything work correctly until it warms up?

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greasytshirt

Moderator
Staff member
Mechanic
Thinking about this further, I doubt there's a harness fault. Those aren't network codes.

Go into the engine ECU customization menu and set the set amount to 2.2. Then, go to the diagnostic menu, open data monitor, and monitor the inlet and Outlet sensor voltages, along with def injection quantity. Press the regen button. Once everything heats up you'll see the sensors initialise. When def is injected, you should see the outlet reading drop lower than the inlet and stay there. The readings should not oscillate. Oscillation indicates a failed sensor.

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rgf451

Seasoned Expediter
Owner/Operator
Thanks, I did that and replaced the sensors. Finally came in and got the job done today (they were on back order according to the dealer). Cleared codes and none returned. When I monitor data, everything looks good until suddenly the exhaust temperature sensor dpr outlet starts reading -490°. That's not normal, correct?
 

greasytshirt

Moderator
Staff member
Mechanic
Thanks, I did that and replaced the sensors. Finally came in and got the job done today (they were on back order according to the dealer). Cleared codes and none returned. When I monitor data, everything looks good until suddenly the exhaust temperature sensor dpr outlet starts reading -490°. That's not normal, correct?
Are you monitoring data through the BCU? If yes, then you're seeing a normal phenomena on that particular line of data. If you want a real reading, look at DPR outlet temp through the ecu, not the bcu. Nothing is broken. It's a programming error.
 
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