Hi all, I am working on a 2014 122SD and I am having trouble finding one of the J1939 data link terminating resistors. I have 120 ohms of resistance on the data link. I found one resistor in the B pillar on the driver side but cannot find the other. Any advice?
What other options does your truck have. We have virtual technician, so our j1939 circuit runs from the ABS/RSS module on the right frame rail, forward to the cross member just behind the cab, across and up to the left rear bottom corner of the cab, under the driver door kick plate, across the dash to the passenger door kick plate, back to the right rear cab J-post, up, back forward above the right door, then to the VT com box located in the top center forward overhead compartment. We ended up tracing that #### circuit trying to find a pinch. Once it was found the driver said, “We’ll that makes sense, the issue did show up after I re-tightened the screws for the overhead compartment”
Thanks for the info. It has a DD15 with an Eaton Ultrashift behind it. I saw a TSB for the virtual assistant and checked to see if it has one and it does. I have checked at the CPC, TCM, VT, and ABS module. All have 120 ohms on the J1939. If I unplug the resistor at the driver side B piller they all show open indicating the backbone harness is good to all of their “legs” of the harness so I am thinking the issue is going to be close or at the other terminating resistor but I have looked for about 4 hours and haven’t been able to locate it.
Make sure it doesn't have an old qualcomm harness hanging off the back of the cab. If so, the pins corrode and the j1939 high/low bridges.
