Working on a 648g3 skidder, getting codes f475 fuel derate and f477 security violation. Ecu has been replaced but having same issue. No other fault codes are coming up.. anyone with experience on this issue? Tia
Welcome to HEF 89 ! Serial number? Is this something that recently started? Also check your fuel gauge and back up alarm circuits for shorts to ground. These circuits have been known to cause those codes. Check in your monitor for any other codes active or stored and report back.
Thanks! fuel gauge and back up alarm aren’t working either but then again they haven’t in forever. And no other codes are coming active. Serial #dw648gx590900
Kenneth’s i think my issue is in the monitor itself, iv traced the harness back to the fuel sender and alarm and it checks out. I’m also not getting any other fault codes
First press and hold the menu button until service mode pops up. The you will have the option to clear the codes. Clear them. Then unplug the backup alarm/fuel sender harness from the transmission harness. Then run machine to see if the codes come back (note that you will get an open circuit code for the sending unit).
I’ve done that. Codes stay active
First make sure the "CAN" wires from the monitor to the ECU are good (they will be green and yellow twisted wires). Make sure they are not open between the monitor and ECU. At the service advisor plug check the ohms (key off) from across pins C and D (at the plug they might be purple twisted wires). Should see 60 ohms. Then with the key on check voltage at pin C and D. C should be approx 2.6 V and D should be approx 2.4 V. If all checks out then you most likely have a monitor problem. The software within it became corrupt somehow. If you remove it and look at the back is there a sticker with a part number? If the part number is AT311743, AT315430, or AT301858 you will need a new monitor. If it is AT363806 it can be reprogrammed which I would try that route before replacing it. If you decide to purchase a new monitor and your old one is one of the part numbers mentioned above you will also need AT364018 adapter harness. I also recommend writing the part number from the old monitor on the back because any reprogramming of it would require the original part number. New monitor would have to be configured. Ask your dealer to print the instructions for you if they don't come with the new monitor.