Hello, I was wondering if anyone could maybe help out or if someone had the same problem. Basically, the fault code appeared on my excavator 128 pid 91 9, its regarding the accelarator pedal position, the excavator itself moves but the bucket doesn't turn, the excavator randomly shuts off sometimes. I investigated the fault code and was looking at the wires, basically the J1708/J1587 was tested and it was good, I encountered the problem during the CAN bus check on the J1939, when checked it was 0,2volt and 60ohm, I searched for what it should be on the internet and it said that it should be on 2-2,5volts when the ignition is on but mine is only 0,2volts on the - and + J1939 wires. I really want to figure this problem out having a headache about it for 2 months, if someone could help it would be appreciated.
You might be having a voltage drop. Can you run a external wire around the circuit to termination point to see if the problem still persists.
The EECU is not seeing the rpm request signal from the VECU or TECU. You will need to check both TECU and VECU for powers and grounds and if they are communication on both busses. You will need to diagnose both the J1939 and the J1587 can networks. Lastly it could be one or both TECU or VECU.
I just checked each of the J1939 wires straight to the ground and both of them we're showing around 2,4volts on idle, so I guess that rules that out, since both J1587 and J1939 are checked now and seems completely fine I have no clue what else could the problem be...
Yeah, well I had both the EECU and VECU delivered to a guy who deals with excavator electrical issues, he checked both of them and it was fine on his end, he even re-installed the programs on the ecus. Still, when delivered we put it back on and it still doesn't work, now J1939 and J1587 are checked out and they're working good, what could the other possible problems be?
I'm not sure how he tested them but Volvo does not have a way to verify this communication. The issue is not with the EECU but with either or both the VECU and TECU. Have you verified powers and grounds to both ECU's and can you see both in product information in TechTool?
I was checking everything with multimeter since I don't have the programs and cables to check it with techtool. Well, so you basically saying it could be still the vecu or tecu fault, because battery is 24v every wire is checked it shows what it should.