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MT855C no throttle or engine information

768 Views 13 Replies 5 Participants Last post by  lanwickum
In law has a MT855C. I went to look at it closer yesterday. I have CAT et and downloaded a PDF service manual from agco.

Engine ECU was replaced. CAT dealer bench tested and said they couldn't even hook up to it. Bench flashed the new ECU. Customer installed it and had a tech come and program injector codes and engine timing calibration. Check through settings and couldn't get throttle to work. Eventually had to leave for the night. Agco tech was there for a while and left saying he couldn't do anything.

Currently it has no throttle control. No engine information other than RPM on the displays, dash and armrest. It does run and shift and hydraulics work, only at 1000rpm.

Any MT800C experts that can point in some direction?
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Need to program the personality module or you’ll have no throttle
personality module? Can you tell me how that is done? With Agco EDT? What is the personality module? what does it do?

Thank you!
I have CAT ET. Everything on the engine ecu has been programmed and working that I know of and can find. CAT dealer flashed it on the bench according to ser#. Ser# and software# match up as winflash says they should. Did have injector and timing stuff done after engine ECU was installed. Synced clocks between machine (powertrain) ECU and engine ECU.

This machine appears to control throttle through J1939, I think. Throttle goes into armrest ECU. No direct connection to engine ecu. Pin 66 is empty on engine ECU, pin 68 is used for decelerator and is working when watching in ET.

Am I still missing something here? What would the password generator do for me? I might have one.
Are you sure you have the right flash file? That’s exactly what I had when I flashed an industrial C18 engine. Ran and started fine just no communication with the tractor.
I double checked the software # with my winflash program. It is correct. Doesn't mean it flashed properly. I have never seen a flash file flash wrong. I don't have the file to reflash it. That is on the list once I can double check things on the Agco EDT side of the machine. Hoping it is engine ecu ser# not matching on agco side or something simple. Hoping someone has been through this and knows what I am missing.
Spent the afternoon with a different Agco tech. We made phone calls, reflashed every ECU on the machine swapped armrest ECU with a different one. Checked connections, ohm CAN wires. Everything we can think of. We both believe the engine flash file is wrong. CAT only has one file available. Even back in 2011 when my ET software is from. Agco says they have nothing to do with the engine and have no file for it. They do have a spot in their trouble shooting that mentions this problem with same symptoms. "Engine is flashed with the wrong file". Ya, ok.....

Anyone have a MT855C engine flash file available or can tell me what file# is on their MT855C? Current file # on new ECU is 2762681. Tractor has been down for a while. Seeding is happening, they are organic and need it to summer fallow also. They are using my tractor now. Message me on here. I check fairly often. Would be willing to pay for a tune if it might make it run properly.
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Are you sure you programmed the personality module? Will just be done in the parameters page at the bottom.
Otherwise I would need engine serial to see what I have available. There are very limited flash files for those tractors. I've only done a few.
I only find configuration settings. I found no settings to fix the problem. I am the second guy to look at it. Also spoke with CAT dealer that used to sell these tractors. Engine ser# is JAS00981 Got anything to help that would be great.

Plan to go take a third look today. People keep telling me to program the personality module and find no place to really do that. So, I will go look again. Maybe get a tuner guy on facetime or something. Message me on hear if you think you can help. I'll check my messages while I am there.
Thank you
Flash file is correct for the serial number.
What is the powertrain data link set to? That dictates what CAN communication standard it uses to talk to the tractor.
Post up pics of your parameters
I’ll grab ET and plug it into the tractor while I’m seeding and have a look. I’ve got all the flash files including the older ones as well. Pretty sure it will jog my memory it’s been about 4 years since I’ve messed with them. Just don’t remember having to mess with any settings after.
So have you flashed this file through ET plugged into the tractor?
Had some help from a guy that does tuning. He sent me a different flash file from another MT855C. It is a mismatch so engine won’t start. I now have engine information on dash and armrest that I did not before. ET shows desired engine speed change with throttle. A few weird codes are now gone. I am almost certain CAT and Agco have lost the correct flash file. Hope they can find it.
The old ECU is bricked, so I am told. Can’t even hook up to see the file # that was on it.
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