I know you’re trying to help, and it’s laudable. If the search function worked better you could see the test procedure I went through after getting the runaround from the dealer and FCA years ago. Everyone who has complained and followed my procedure has gotten the same results. I ran the trailer connected to the bed plug, with a dvom connected to the bumper plug. Had a man in the right seat recording voltages at various speeds when applying the brakes. All results were consistent and repeatable. The controller pulls voltage out as the vehicle slows. Generally below 30 mph it’s only 7.4 volts at best. That’s why you can’t lock the trailer with the manual lever in a parking lot test. I know it’s hard to understand how the engineers could be so stupid but they obviously haven’t ever towed anything coming close to the trucks capacity.
I'm frustrated for you and despite telling myself to let it go, here I am again. My problems are I'm a persistent type A, I'm laid up for 12 weeks (2 weeks into it) in bed from surgery, and I'm bored to death. Also, you're right about not getting many hits on the TDR website on the ITBC and problems. Going to Google it on WWW and see what hits come up.
Is this a fair summary of your problem?
- Failure of the ITBC to satisfactorily stop your trailers, especially at low speed?
- You've had the ITBC problem since the truck was new (2015)?
- You've turned the truck into the dealer several times and they could not fix?
- Did you elevate a claim to FCA and go to arbitration?
- You've conducted extensive testing on the truck and trailer, concluding the problem is with the truck?
- The truck ITBC voltage output range is 7.4 VDC to ~11 VDC pre your testing?
- Do you know min voltage needed to lock up your trailer brakes at low speed?
- There is nothing more that can be done to improve your situation, without some fix, patch or software/hardware update from FCA?
Overall facts as I see them:
- Some folks are having legitimate problems with their ITBCs
- Many folks are not having any problems with their ITBCs
- There has been extensive analog testing accomplished on the ITBCs
- The folks who have problems with their ITBCs have not been able to resolve them
- No apparent solution at hand
Do I believe you and some folks are having problems with their ITBCs, YES!. But because there are so many of us who are towing heavy with ours, leads me to believe this is not a design problem. Otherwise, all of us would be experiencing it. I believe about all of the analog testing possible has been accomplished. But because there are so many of us who are towing heavy with ours without problems, leads me to believe this is not a design problem. Otherwise, all of us would be experiencing it. So what does that mean, at least to me? There is a complex problem with the truck, in my opinion likely within the truck's data network.
Yesterday, I went back into the FCA Service Manual and found the ITBC is connected to the truck's CAN C BUS via dedicated twisted pair data circuits, like a dedicated Ethernet network. Ethernet network twisted pair wiring is extremely sensitive to the number of twists per inch, precise termination, spotless clean connections. And in the real world, the way to test and certify is special data test equipment the transmits and receives data streams and measures data loss. Ethernet, if that is a fair comparison the Ram truck, is very sensitive to interference, induction, and voltage induced noise. It's likely the trucks twisted pair circuits are shielded and the sheath is grounded to a dedicated isolated ground. I doubt any existing
So, what does this mean in my opinion? Its plausible a few folks may be having ITBC problems related to the truck's network problems. What are the options, again, in my opinion:
- Live with the problem; possible risk of an accident.
- Elevate complaint to FCA and consider NTSB to seek FCA fix
- Install an aftermarket brake controller and dedicated trailer brake wiring to bypass truck ITBC and wiring entirely
- Try unconventional troubleshooting steps that may not work: reseat connectors with dielectric grease, check, clean, tighten grounds with dielectric grease, and inspect cables for nicks or damage.
Finally, I'm not a master IT tech, although I have moderate IT skills, but I had tech controllers, field engineers, EEs, and sys admin available support solving complex data problems on government systems in the past. I'm still ready to help and will continue to learn the ITBC in the background.
BTW, you're not alone dealing with complex and potentially dangerous issues: my 5er is in the shop for a "complex" problem that the Lippert auto level system collapses front landing gear after several weeks of sitting, no leaks found by service dept. I've had problems with the Lippert Auto level system entire time of ownership, dropping while driving, collapsing while parked. 2017 Ram in the shop to try to activate guidelines on the factory backup camera, option which is disabled by FCA. I persist!
Cheers,
Ron
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