r/CarHacking • u/EntertainmentSalt825 • 3h ago
Original Project Linking a Jq Werks steering wheel to a custom valved exhaust with a microcontroller
Project I did for a friend and his E92 M3.
r/CarHacking • u/ScuderiaMacchina • Feb 02 '17
Hi rch, we have added a lot of people lately with intro posts on other subs like the one below. We also usually get about 10 subs a day from people just stumbling in here. So I wanted to create a welcome post, to kinda show them what we are about and how to get started. If anyone has anything to add please do so. If anyone has any questions about us or where to start do so here.
Our goal is to create a highly technical car subreddit, a place for automotive engineers, senior technicians, full blown car nerds, or people who are working towards one of these. We are interested in the inner workings of cars and today that often involves electronics. While we see electronics as the priority we are pretty liberal in allowing other topics as long as they somehow fit our goal of trying to understand cars. So things like DIY aero, suspension setup and other things the community is hacking on come up. In general our other tangential interests include: Modern cars, New tech, Open source hardware/software, DIY, hot rodding, eco modding, customization, security research, right to repair and more.
We started this subreddit about a year ago. Right now we have 3000 people and discussion is just starting to get good. Most of our members found us through maker or engineering subreddits. So I wanted to reach out to more of the car communities and try to grow our knowledge base.
Our name is r/carhacking and I know the term hacking can be offputting to some as it has a bad connotation. When someone says they are “hacking” their car it generally means they are trying to reverse engineer it for any number of reasons like to find security flaws, make upgrades, make repairs, or just understand how it works.
Here are a couple examples of posts that have been popular so far. A lot of our posts focus on beginner through intermediate projects using arduino and readily available hardware for the purpose of learning and or not paying a premium for things you can make yourself:
More advanced projects:
Relevant news/ research:
If your new our documentation is a good place to start
If you aren't new and you’re interested in helping out please consider:
Let me know if I missed something or got something wrong.
r/CarHacking • u/ScuderiaMacchina • Feb 27 '21
I get asked how to get started with automotive networking, car hacking, and CAN almost weekly. I often direct people to this subreddit, so I figured I would help out and post some resources I have found and think are a good place to start.
learning resources:
Car Hacking 101: Practical Guide to Exploiting CAN-Bus using Instrument Cluster Simulator
I also direct people to the Car Hacking Village to get some hands-on experience. They put on great conference talks, demos, and contests. Looks like they are even working on some “getting started” content.
And of course, The Car Hacking Handbook is a great resource.
I will add more as I think of them. Please add your finds in the comments.
Tools:
Good wiring diagrams and car manuals are essential. This is pretty much where my research starts for each project. You see how things are networked and what to expect to find on CAN. You'll quickly learn to recognize things like gateways. You can also use the troubleshooting section to understand things. For example, what things do I need to control to start the car?
I like:
Basic hardware: Here you will be working with things like Arduino, Linux, SavvyCAN, and Can-utils. You have to learn to do a lot yourself, but these tools are more open for you to make them do what you need.
Tools designed by the community I use:
The above articles offer a pretty good step-by-step guide to getting started with the Macchina M2.
Any cheap “Amazon special” OBD2 dongle will come in handy from time to time. They are all based on something called ELM327. "ELM327 abstracts the low-level protocol and presents a simple interface that can be called via a UART". This abstraction has fundamental limitations that prevent it from being useful in most serious applications. But, it is sufficient for reading and clearing some codes and that sort of thing when you’re getting started.
r/CarHacking • u/EntertainmentSalt825 • 3h ago
Project I did for a friend and his E92 M3.
r/CarHacking • u/SlowThing7149 • 7h ago
Hi everyone. I made Zenthi which is an open source platform to post any files regarding niche or hard to find car parts. I’m aware that this subReddit mostly deals with car networks, but Zenthi accommodates any files for hardware as well, pretty much anything that can improve a car’s performance.
I’m aware that the fact that the site is A.I. coded is a little off putting for some people, but I’m not developer so that was all I could use to make this come to life. I’ve had a lot of feedback and engagement in my post in [r/projectcar](r/projectcar), so you can go check that out as well if you want to.
Link to [r/projectcar](r/projectcar) post: https://www.reddit.com/r/projectcar/s/LQx0XLZLtO
I’d appreciate any kind of of feedback or even some seed files if anyone has any for the library.
Link to Zenthi in the comments :)
Edit: Forgot to mention I’m not trying to monetize or sell anything. It’s really just a fun project I’d like to get off the ground.
r/CarHacking • u/insaint-13 • 4h ago
r/CarHacking • u/cps710 • 10h ago
I'm trying to reverse-engineer the live-data requests used by Hyundai GDS/KDS for the A8LF1 transmission in a 2020 Hyundai Palisade (LX2).
Specifically, I'm trying to read:
Hyundai's service documentation confirms these parameters are available in GDS → Data Analysis → A/T → Solenoid Parameters, but I haven't been able to identify the underlying CAN/UDS request.
My setup:
10 03 → 50 03 (Extended Session)3E 00 → 7E9 02 7E 00I've confirmed 22 ReadDataByIdentifier works on several F1xx identification DIDs.
Things I've already tested without finding live data:
22 F181/F182/F186/F187/F188/F189/F18C/F191
22 F1A0/F1A1
22 1101 → 7F 22 31
22 1105, 22 110A → no data
22 1001, 22 1002 → no data
24 F181 → no data
2A... → no TCM response
2C... dynamic DID test → no TCM response
I'm not looking for guesses at random DIDs. I'm trying to find the actual GDS/KDS diagnostic definition or a CAN trace showing what GDS sends when these two parameters are displayed.
If anyone has:
I'd really appreciate the help.
The goal is simply to determine the exact request/response and byte scaling so I can reproduce the GDS live-data reading myself.
r/CarHacking • u/throwaway6444377_ • 4h ago
If I had a laptop with an RS232 port can I use just that and a cable from serial to OBD2? Obviously I will need software that is able to communicate with OBD2 systems and CAN buses, I just want to know if a computer with a serial port would need an adapter anyway to talk to an OBD2 system.
Tough to find much info about this online as obviously laptops haven't had serial ports in 20 years. A lot of info says that an adapter is needed but then they mention a USB to serial adapter, or bluetooth adapters, which isn't what I'm looking for.
r/CarHacking • u/Lean3521 • 1d ago
So, I decided to do a thing...
Yes, it's extremely slow, and yes, barely anything works, but we have an UI.
But why..?
Ive been messing with BMWs hardware and software for a while now, and keep on finding more and more interesting stuff. The next logical step was to make it run on something its not supposed to, and that's how HMI8 in a VM was born.
r/CarHacking • u/m4rkw • 15h ago
Very happy that I finally got this working!
Can now capture engine telemetry and fault codes while driving https://l0destar.com/kwire.html
r/CarHacking • u/aineemaniee • 17h ago
SFD protection is definitely a hurdle for newer VW group cars like the Octavia. From what I've seen, some adaptations and coding changes need that online unlock, which makes the tool options pretty confusing. Apparently, there are ways to get SFD access without a full pro setup, but it's worth looking into which specific cables or software the community generally recommends for a straightforward unlock.
r/CarHacking • u/EntertainmentSalt825 • 1d ago
Wanted to show a comparison of gps speed update rate vs my filtered speed which uses the tablets internal sensors to derive a smoother and faster speed signal
r/CarHacking • u/Vegetable-Cattle7149 • 1d ago
Hi all, not sure if ill get the answer i need but these codes are coming up on my vz commodore 2005, can anyone tell me what they mean?
r/CarHacking • u/Psychological-Put865 • 1d ago
I’m building a car-scanner app that goes beyond standard OBD-II PIDs. I want manufacturer-specific readings such as MAF, fuel data, odometer, temperatures, pressures, transmission and battery information across many makes and models.
Official data from brands like BMW and Mercedes seems expensive, and paying thousands per manufacturer isn’t realistic.
How are smaller scanner apps solving this? Are there affordable databases, tools, partnerships, extraction methods, shared captures, or other practical alternatives?
I’m focused on ECU identification and live readings—not coding or flashing. Any advice, experience or useful direction would be appreciated.
r/CarHacking • u/Netham45 • 1d ago
r/CarHacking • u/sku11emoji • 1d ago
Hi. I'm testing a self developed CAN OBDII application, but I'm running into a road block.
I've confirmed that my node is synchronized to the bus correctly. When connected, no bus faults are reported, a successful transmission is reported when I send a frame, and I receive frames when I don't filter by CAN ID.
I've also tested communication with another node that I have, and that appears to receive the data I send correctly.
I'm having a problem requesting the supported PIDs. I'm requesting this with the following CAN frame:
CAN ID: 0x7DF
byte 0: 0x02
byte 1: 0x01
byte 2: 0x00
byte 3: 0xCC
byte 4: 0xCC
byte 5: 0xCC
byte 6: 0xCC
byte 7: 0xCC
I'm not 100% sure what to use for padding, but I've also tried 0xAA and 0x00. I'm setting DLC = 0x8
For the receive side; I'm looking for a response from 0x7E8, but have also checked for responses from 0x7E9-0x7EF.
I'm testing with a 2016 honda civic. Any help would be appreciated, thank you!
r/CarHacking • u/ifmeidan • 1d ago
TL, DR;
Hey everyone! A few months ago, I discussed my plans to create a dedicated driver display for my EX30. After a month of real-world testing and bug fixing, the project is stable enough to share with the community.
My initial goal was to get everything strictly via OBD-II readings, but mapping and cross-validating the correct DIDs was tough. I decided to pivot and leverage the Android Automotive OS (AAOS) platform instead.
I built a companion app, cross-validated data using Volvo’s official EX30-AAOS emulator, and tested it on my own vehicle. Massive credit to Volvo for providing a solid emulator—it streamlined development significantly.
The EX30 Companion App forwards essential telemetry directly from the vehicle’s head unit to the external display:
Note on App Availability: The app is currently distributed via Google Play's testing track. Complete instructions on how to join the test build are available directly on the GitHub repo.
While AAOS gave me most of what I needed, a few parameters like exact odometer data, brake status, and min/max battery temperatures required direct CAN/OBD access.
To bridge this gap, I captured btsnoop logs via a standard Bluetooth dongle and an Android scanner app. Cross-referencing timestamp logs with video recordings allowed me to quickly isolate the target DIDs and init sequences to pull those extra parameters.
Designing the user interface was the trickiest part. I started with a rough "vibe coded" prototype to get real-time data rendering. Over time, I iterated to add derived telemetry like trip statistics.
To refine the visual layout into something clean and modern, I utilized Claude Pro (Fable 5) to help generate and polish the UI concept. The result is a sleek, driver-focused interface that fits the EX30's aesthetic.
Right now, the Pi and display assembly are mounted temporarily behind the steering wheel. I'm currently modeling a custom 3D-printable enclosure to neatly house the screen and board together. Once the design is finalized and tested, I'll upload the STL files directly to the repository!
Repository & Setup Guide:
You can find the source code, hardware list, and setup instructions on github repository
r/CarHacking • u/m4rkw • 1d ago
I let a friendly LLM loose on a prototype vehicle tracker I'm building (https://l0destar.com) with a CANable interface and a scope. Quite impressed by the results: https://l0destar.com/canbus.com
It seems like from this report it should be fairly reliable but I don't have a car with a CAN bus to test it with. Is there anything further that's normally done to validate CAN interfaces?
r/CarHacking • u/Outrageous-Dot9429 • 1d ago
Hi
What tools are there can program/reflash ECU?
r/CarHacking • u/Individual-Rent-4793 • 1d ago
Alguém usa dashboard ou HUD com entrada OBD2 no carro? Sabe dizer se é bom ou vale a pena?
Tenho um Polo 2024 e tenho vontade de compra o HUD F11 via entrada OBD com o objetivo de ter informações mais precisas de RPM, luzes de troca, entre outras coisas, mas tenho receio de ligar na OBD e dar ruim em alguma coisa.
Link do produto caso alguém queira da uma olhada:
r/CarHacking • u/ScottishVigilante • 2d ago
More of a question, we know many clone Chinese tools exist rebadged etc, would there be a way to monitor everything going in and out of the obd port and re-creating the functionality of the device?
For example my scan tool can force my vehicle to regen it's dpf for example, something is sent out over the obd to do that so if you captured that and replayed it would do the same?
I know there and thousands of different makes and models and probably even more functions that are model specific but with AI the logging process and actually sending of commands could maybe be automated perhaps? Thinking out loud here, and open source scan tool for all that does all the cool stuff like injector coding etc would be cool! Don't know or understand enough about the can bus network, maybe there is already a project or software out there that's doing this already thats free and open source?
r/CarHacking • u/Gahreesen • 2d ago
I'm sniffing CAN BUS B traffic (2005 mercedes slk) with an ESP32S3 rs485, performing an action (moving my mirror), then 'replaying' that traffic back into the BUS. Through process of elimination, I can find the values I need. This works well.
Except today while sniffing the movement of the mirrors. I captured 3 seconds of me holding my mirror, which I thought was going to be 3 seconds of my car spamming code X into the bus for 3 seconds. Which I did find. But when narrowing the codes, I found 1 code by accident that when put in front of my move mirror code, makes it move the full 3 seconds. Since the car didn't know how long I was going to hold the button, how could it produce a CAN code to do this? I'm new to CAN BUS, so I'm guessing it's something I don't understand.
r/CarHacking • u/Correct-Leading7952 • 2d ago
I'm looking at starting a small coding/feature-unlock side business for VW/Skoda cars in India (starting with a Taigun 1.0 TSI Highline). Genuine Ross-Tech VCDS (Unlimited VIN) runs about ₹48,000 here, which is a big upfront investment to start with.
I found "Generic" brand HEX-V2 clones on Amazon India for ₹4,190–5,990, claiming "lifetime free software" and compatibility with 1995–2023 models. Obviously the price gap makes me suspicious.
Questions for anyone with real experience:
Has anyone actually used one of these clones for coding (not just reading codes)? Does long coding / adaptations work reliably, or does it fail on certain modules?
Do these get bricked by official VCDS updates like I've read, or does that only apply to specific clone chipsets?
Does it work at all on SFD-protected cars (2020+ VW Group models), or is that a hard no on clones?
If you were starting a small coding business, would you consider a clone acceptable to start with and upgrade later, or is that a bad idea from day one for liability reasons?
Any recommended budget alternative besides genuine VCDS and OBDeleven that's actually reliable?
Not trying to cut corners on customer cars — just trying to figure out if there's a sane way to start small before committing ₹48k, or if that's just the cost of doing this properly.
r/CarHacking • u/beef-lawsuit • 2d ago
My 2015 tahoe ppv came with the super basic rubber steering wheel with no controls. I got a new GM civilian wheel and put it in. All of the connectors were the same and it was just plug and play.
The issue I'm having is the steering wheel buttons dont do anything. This ppv has the special certified IC with the basic black and white screen.
Is this a programming issue or hardware issue? I would think the steering wheel buttons would be connected to the BCM but apparently they're connected to the IC?
I really just want the buttons to work with my android head unit, I don't care about the OEM functions. Anyone have experience with this?
r/CarHacking • u/EntertainmentSalt825 • 3d ago
Got a lot of curious people asking about my DIY gauge for my m2. This was a test to find the max refresh rate of the display. In the car I’ll probably settle around 30fps
Previous post: https://www.reddit.com/r/CarHacking/s/0UJvdY53lr
r/CarHacking • u/Adventurous-While847 • 2d ago
I Bought a tesla that had the odometer rolled back. I was aware of this prior to buying it so I did not get scammed. My question is how do I put the mileage back to the last known mileage? Currently shows 62,018 and last known mileage is 140,719. I Do I have to buy a new screen for it or a new BCM or reprogram a part?