SPN 641 FMI 9

[billharkey]

I keep getting the above error in my isx 2250 when starting. After I run about half an hour, I shut the truck off then restart and it goes away. 4 days in a row so far. I took to shop for diagnosis and they said it could be harness, actuator or ecm. I know the folks on here are pretty wise about engines.

Its a factory reman that i just had overhauled in december. Actuator was replaced in december also. I had a delete done to it while it was in shop. Been running great so far. I'm just worried it may go into derate if the light doesnt go off one time.

I thought of just replacing harness and see if that works. and take it from there.

Any ideas??? Thanx in advance

[Rawze]

SPN 641 FMI 9 = J1939 communications lost for turbo actuator.

(05-15-2021 )billharkey Wrote:  ... had a delete done to it while it was in shop. Been running great so far.
...

-- That is what most people say when they have a bad deelte... they always swear it "runs great" ... until it eventually blows that head gasket due to excess internal friction and dropped liner.

Who did the de-mandate?. ..and where?. What mechanical mods were done too?.

and what make/model/year truck?.

[billharkey]

Delete done at {unknown quality shop}.

Mechanical mods...not sure what was done as far as mods.

Getting ready to retire, gonna be selling it soon. Just want it to run a bit longer without major expense.

Do you think changing harness might help? I'm thinking off a broken wire that connects when it heats up. But what do I know.

[Rawze]

=- Priority one would be to pull a copy of the program out of that engine and e-mail it to me for review. Someone has to be an idiot if they think for one damn minute that they should be trusting that programming "out of some unknown place in Texas" .. and if your getting ready to retire then you should fix it so that the next person does not end up with YOUR headache! >>>> AS THERE IS NO EXCUSE TO RUN AROUND WITH SAND IN YOUR OIL AND HOPING FOR THE BEST... because that is exactly what your likely doing!.

NEXT: its a damn CM2250... the files are public and free to fix the programming properly if you have an adapter and a laptop!... there is no excuse for it!!!.. plain and simple!

----

With unknown quality delete programming.. that very well may be a big part of your problems... but who knows for sure at this point. Just because it might have seem to worked somewhat ok to you for a while does not mean it will stay that way... or has ever been right.


NEXT: IF THOSE MORONS AT THAT DELETE SHOP HAVE UNPLUGGED THE ENTIRE HARNESS FOR THE DPF SYSTEM UNDER THE TRUCK... THIS MAY BE A BIG PART OF YOUR ISSUES TOO!. Get yourself an OHM-Meter and measure the resistance (keys-witch off) of the yellow and green twisted pair wires out at the engine harness 3-pin triangle-shaped J1939 connector (Can-Bus#2) located on the drivers side. It is called the "weather-Pack" connector in this photo...




... and see if it is roughly 60-ohms, or 120-ohms, or something higher! (key-switch off). Also, Crawl under your truck and see if the main harness going to the SCR/DPF, etc. controller is unplugged somewhere.

THE Can-bus#2 is the one used for the turbo actuator and other engine hardware. It requires 2 terminating resisotrs to prevent noise and problems with communications. One of the terminating resistors is in the turbo actuator itself on an ISX ... and the other is usually located down under the truck at the DEF controller or at a NOx sensor at the other end, this especially the case for CM2250 trucks that have that second DEF controller.

Don't give your truck an excuse to act up out of nowhere... check things properly.. FIX ANY HALF-ARSSED DELETE PROGRAMMING,... etc. and verify that the J1939 cab-bus#2 is proper and that the terminating resistors are both in place. Otherwise, your doing nothing but piS#ing up-wind.

In fact, I had someone not 3 days ago who said they had their entire harness unplugged from the "delete shop" and after a while, developed this same type of errors.. only to find that one of the J!939 terminating resistors in the network WAS MISSING because the s$it was unplugged. On theirs in fact, the whole harness cut/lopped off under the passenger side of their truck and plugs just hanging there.


- I can lead the horse to water... but some of ppl here lately do not want to hear reality and listen ... Which one are you going to be?.

[DieselKid]

Had this same issue just last week, only 120ohms at the engine data 3 pin. Found the other terminating resistor at def harness missing. Installed that and problem solved. Rawze hit the nail on the head!

[billharkey]

I will try to get info from shop, and check myself.

Could any other shop check this stuff out? Where are you located?

Thank for all your help and advice. I appreciate it. I want to get this fixed and NOT pass it on.

[DVT873]

(05-15-2021 )Rawze Wrote:  ...
THE Can-bus#2 is the one used for the turbo actuator and other engine hardware. It requires 2 terminating resisotrs to prevent noise and problems with communications. One of the terminating resistors is in the turbo actuator itself on an ISX ... and the other is usually located down under the truck at the DEF controller or at a NOx sensor at the other end, this especially the case for CM2250 trucks that have that second DEF controller.

...

So the 3 pin plug your pointing to is the direct hookup for INSITE? The engine and aftertreatment are their own network. Engine data gets sent out to the truck CAN from the ECM. If you plug into the truck 9 pin you will see all the modules on the truck, ABS, Engine, etc. If you plug into the 3 pin you will only see the engine/aftertreatment dats. Is that correct?

[Rawze]

(05-16-2021 )DVT873 Wrote:  ...
So the 3 pin plug your pointing to is the direct hookup for INSITE? The engine and aftertreatment are their own network. Engine data gets sent out to the truck CAN from the ECM. If you plug into the truck 9 pin you will see all the modules on the truck, ABS, Engine, etc. If you plug into the 3 pin you will only see the engine/aftertreatment dats. Is that correct?

that is correct. There is 2 seperate J1939 networks.

* Can#1 is for the dash, the truck/vehicle cab controller(s), ABS system, etc..

* Can#2 is for the engine components like any NOx sensors, the DEF controller, Turbo, DEF tank sensors, etc.

as far as hooking up with Insite.. you could use either one of them.

[billharkey]

For anyone interested, replaced actuator and that fixed it. Thanx for all that responded.