Codes- 5856-9 and E1389 (1) downloaded product status report and under system communications status is stating (Device 1 c4.4 is unable to communicate with Device 2 Def tank quality sensor.) Also stating (device 1 c4.4 is unable to communicate with Device 2 aftertreatment def controller #1.)
5856-9 is the key. The J1939 datalink communication between modules has been lost. The E1389 is a consequence of that. See the attached troubleshooting procedure. You may find that you also need an electrical schematic. If that happens then just ask.
If you could forward that schematic would be most appreciated.
I found the schematic I need. If the communications diag checks out is there a way to test the def head? or should I just replace it at that point.
You need one of the forum aftertreatment system experts to advise you on that. TBH is ECMs are not communicating that is the most likely issue causing the Codes.
If your wiring check out ok, you’ll need to replace the DEF quality sensor, there is a sensor kit available. No way to test to my knowledge other than a known good sensor.
All procedures passed on the can Data link test besides in step 1 checking voltage on pin 3 and 4 at the def head connector I didn't have any voltage, the continuity was good on the key switch line between the ECM and DCU though. I am going to move onto the electrical power supply test because I also didn't have power on pins 56 59 and 62 on the DCU. This kind of has me dumbfounded though because I don't have any codes for those conditions. The only codes still on the machine are 5856-9 and E1389
Im Also performing aftertreatment power relay test.
Issue resolved. Kind of feel like a dumb A. First thing I did before starting the diagnosis for 5856-9 and E1389 was continuity check all the fuses and they all tested good. after going through all diagnostic procedures for 5856-9 and E1389 I ended up tracing the power wire for the aftertreatment relay back to the fuse panel to fuse 8 and checked for power across the fuse and found that although it passed for continuity the fuse was blown, replaced the fuse and the machine passed the aftertreatment functionality test. During the whole diagnostic procedure the only codes on the machine were the 5856-9 and E1389 there were no codes related to power supply for any of the aftertreatment devices. I hope this helps someone in the future. Thank you everyone for all the help.
Not the first time I've seen that. The only true test of a fuse IMO is whether it will pass the rated current for the circuit. A failed power supply to a device most often does not cause any sort of Code. Well worth bearing in mind.
Found the exact same issue on Komatsu 200 excavator. Tested the fuse with multimeter and all good, but found out 3 hours later that no power at first plug in connection from fuse. Fuse was blown and lightly welded back together. Decided would never get caught like that again. LOL Simon C
Two very good points for mechanics to keep in mind when doing troubleshooting. I always start at the battery box to make sure a bad connection there is not a problem before heading to fuse panel and relay panel. Of course checking for codes is there also. Glad HRS at least answered back what was going on. Simon C