Jump to content

Recommended Posts

Posted

Hi everyone. I have a 2018 silverado 1500 with the integrated trailer brake controller. Recently I have been getting the service trailer brakes warning on the dash and trying to resolve it. Originally when i went to the gain screen on the dash, no numbers would show and it was completely dead. First test was to replace the module under the spare tire based on everything that I read which did not resolve the issue. I had the original battery in the truck and I knew it was starting to show signs of needing to be replaced which I did. Once that was done, it changed the behaviour of the message. Now when I turn the key to On without starting there are no messages. Once I start the truck I get a message for a split second but the gain screen is functional. I can adjust the numbers up or down without issue. Randomly as I drive though, i will get multiple warnings that i need to service the trailer brakes. As a test, i connected a known working trailer. The truck detects the trailer and the gain screen is alive (no longer grey and is yellow/orange). Hitting the brakes does not activate the trailer brakes at all. Using the slide, my truck brake lights will light up for a split second and then go out, then dash has the following warnings: check trailer wiring, service trailer brakes. I did have the dealer hook up to the truck and there is code U0422-71 from the electric brake control module with a description that it received invalid data from the BCM and P0562-00 from the chassis control module aux. 

Wondering if anyone can point me in the right direction? I also did the ground at the back where the module is under the spare and will be doing the other body grounds from the battery cable as well. As a test a known working dash module was also tested with the same results. Thanks in advance!

Posted

I remember reading a while back that someone fixed this after finding exposed wire(s) along the frame rail. I think the insulation got scraped off and was shorting to the frame. Maybe start tracing the wiring from the rear forward. It will be a pain to do this but might help solve the problem. 

Posted

I did look at the hardness and didnt see anything obvious; can dive into the deeper. Also did continuity tests which didnt lead to anything. Looking for more info on that error and other areas to check.

  • 3 weeks later...
Posted

I believe the only thing that can be monitored is negative electrical current returning through the frame instead of the ground wire. It's just a guess, but that's how your home gfi breakers work and my theory is that is what's going on. I will be watching for what you figure out.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts
  • Member Statistics

    342,758
    Total Members
    8,960
    Most Online
    Randy Ginoza
    Newest Member
    Randy Ginoza
    Joined
  • Who's Online   4 Members, 0 Anonymous, 1,903 Guests (See full list)

  • Latest Articles

  • Posts

    • Paid $2.72 for E85 today.
    • Welcome back! No, it definitely doesn't pass the sniff test. Even "ceasefire" needs an alternative definition these days.    $5.29 at Kroger today
    • That makes sense, and I think you are describing the real product problem. Capturing data is the easy part. If the owner or technician has to manually dig through five minutes of millisecond-level logs, the product has already failed. The device would be at the ECM harness, not at the OBD port, so I agree that data retrieval and event marking need to be thought through carefully. The way I am thinking about the architecture is: The recorder itself should not depend on a phone, app, Bluetooth, Wi-Fi, or cloud connection to capture the event. It should always keep a local rolling buffer and lock the event locally. A button, phone app, or small cabin device would only act as an event marker. If the driver feels a stumble and presses the button 10–30 seconds later, the pre-buffer has to already contain the useful data. For data retrieval, the practical options would be a sealed service USB lead, Wi-Fi download, or a phone/cabin companion device. I would not expect the owner to remove the ECM-side module or work with raw files directly. The cloud or AI side would be for interpretation, not for capturing the event. The truck may have no connection when the issue happens, so the evidence has to be saved locally first. After that, cloud processing could help decode the data, compare it against baselines, and generate a readable report. For the first version, I would keep the automatic triggers conservative and objective: driver event marker bus-off error passive voltage drop / brownout device reset FIFO or queue overflow a normally periodic message disappearing side-to-side communication mismatch, if the topology supports that For “learning normal,” I agree with your point, but I would not want to overclaim it as automatic root-cause diagnosis at first. A realistic first step would be learned baseline comparison for that specific vehicle and operating condition. For example, a value would only be compared against similar conditions: RPM range load / MAP throttle position gear / vehicle speed coolant and oil temperature battery voltage AFM/DFM state, if decoded and validated Then the report could flag things like: this periodic message disappeared compared with its normal timing this value deviated from this vehicle’s normal range under similar conditions the same abnormal pattern repeated after the same type of event the anomaly occurred together with voltage, oil-pressure, misfire, or communication changes But I would still call that “abnormal pattern detected,” not “replace this part,” unless there is enough validated repair data behind it. So the intended product would not be “here is a huge log.” It would need to be an event package: what triggered the capture how much pre/post data was preserved what changed before and after the event whether the device itself reset, overflowed, or saw a bus error selected graphs around the event raw data only as supporting evidence From your perspective, what would make this kind of report useful instead of just another datalog? For example: What are the top 5 parameters or events you would want highlighted first? Would you trust a learned baseline for that specific vehicle, or would you prefer fixed thresholds? How much false-positive flagging would be acceptable before you stopped looking at the reports? What would a one-page report need to show for an independent shop to take it seriously? For misfire, AFM/DFM, oil pressure, or U-code complaints, what would you want the tool to flag automatically?
    • 2024 Silverado 2500 HD LTZ grille no camera Parts list   84603331 84913656 84913657 84913654 84913655 84911567 84911568 85646092 85646093 85797921 85797922   11570637  x10-15   grille/bumper bolts 11546500  x10      grille clips 11571006  x10      push/retainer clips 11546454  x6       nut retainers 11611609  x6       M5 bolts 11610700  x6       molding/trim retainers
    • And use RA's 5% discount code if you buy from them.  google for the code, one is always available.
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...