AI Car Mechanic — Diagnose Car Issues with new Chat Assistant | OBD Codes, JavaScript, ChatGPT (GPT-3)

Mate Marschalko
7 min readFeb 27, 2023

I always wondered what car mechanics did when they plugged in their laptops to my car and were immediately able to see the issue.

This week I decided to get to the bottom of this and build my own AI Assistant, essentially a personal car mechanic I can have a conversation with to diagnose any problem with my car.

I managed to build the assistant in less than 2 days and I think works extremely well!

Check out the demo and see how difficult it is to break it:

As you can see, all you need to do is simply explain the problem and you get your professional advice immediately.

You can even start with an OBD error code from your car which means you can understand and talk about your issue in-depth without having to pay for a professional car mechanic. This is beacuse car mechanics also do exactly this: they plug in a device to your cars OBD port and diagnose based on the info they download. Amazingly, you can buy a £20–30 scanner from Amazon to retrieve any error codes and all other info into an iPhone or Android phone:

OBD scanner you can plug into any car to download read error codes and other info to your phone

The AI assistant works well no matter how you phrase things, and you can have follow up questions or ask advice for 100% unrelated topics, like cleaning spilt coffee on your seat 😁

How does it work?

The assistant uses the GPT-3 model, a similar model that powers ChatGPT to understand your requests. To give context for the conversation for the chat bot, I had to find a large dataset of car related issues with detailed explanation.

The OBD error codes your car outputs via its OBD port that car mechanics use is a good start. Here’s an example error code with the sort information I found for my dataset:



Mate Marschalko

Senior Creative Developer, Generative AI, Electronics with over 15 years experience | JavaScript, HTML, CSS