# Lewis

> Lewis is an AI car diagnostic app. It connects to your car through a Bluetooth OBD2 scanner, reads trouble codes and live data from your car's computers, scores every scan from 0 to 100, and explains the results in plain English. Available on iPhone. Made by Kunolu Applications Inc.

## What Lewis reads
- Trouble codes: Lewis reads stored and pending check engine codes from every engine and emissions computer that responds, on any OBD2 car. On most of the 35 makes we support, Lewis also asks the transmission, hybrid battery, and other powertrain computers for their own codes, one module at a time, and shows which module each code came from. It works with both 11-bit and 29-bit CAN vehicles.
- Live data: On every car: standard OBD2 sensors including engine RPM, vehicle speed, coolant and intake air temperature, throttle position, engine load, fuel trims, and more. With Lewis Pro on 35 makes: manufacturer-specific values your car reports beyond the OBD2 standard, such as transmission or battery data, depending on the model.
- Health Score: Every scan gets a score from 0 to 100 based on the codes found and how serious they are. Lewis Pro adds a breakdown by category and the change since your last scan.
- Supported makes (35; manufacturer-specific live data on all, module-by-module codes on most): Acura, Alfa Romeo, Audi, BMW, Bentley, Buick, Cadillac, Chevrolet, Chrysler, Dodge, Fiat, Ford, GMC, Honda, Hyundai, Infiniti, Jaguar, Jeep, Kia, Lamborghini, Land Rover, Lexus, Lincoln, Maserati, Mazda, Mercedes-Benz, MINI, Nissan, Polestar, Porsche, Ram, Subaru, Toyota, Volkswagen, Volvo. BMW and MINI data uses extended addressing, which scanners such as the OBDLink MX+ support.

## What Lewis does with it
- AI scan analysis (Lewis Pro): Lewis reviews each scan, including your live data and recent scan history, and explains what it found in plain English with clear next steps.
- Ask Lewis (Lewis Pro): Chat about warning lights, noises, or maintenance, and ask what a repair should cost. Lewis knows your vehicle and its recent scans and gives you an estimated repair cost range.
- Pre-purchase inspection (Lewis Pro): Scan a used car before you buy. Lewis runs its full scan and gives you a Buy, Buy with caution, or Walk away verdict, estimated repair cost ranges for what it finds, and a negotiation script. Enter the asking price and it also suggests an opening offer, a floor, and a ceiling.
- Recall check: Check NHTSA safety recall campaigns by year, make, and model. No VIN or scanner needed.
- Scanner check: When you connect, Lewis checks what your scanner supports. If your scanner cannot reach part of your car, Lewis tells you after the scan so you know what was checked.
- Demo mode: Explore Lewis with a sample vehicle before you plug anything in.

## Scanners
- On iPhone, Lewis works with Bluetooth LE (BLE) OBD2 scanners and the OBDLink MX+.

## Free
- Unlimited scans
- Trouble codes with plain-English descriptions and severity
- Health Score for every scan
- Standard live data
- Recall check by year, make, and model
- One vehicle

## Lewis Pro
- AI scan analysis
- Chat with Lewis, including estimated repair costs
- Pre-purchase inspections
- Manufacturer-specific live data on 35 makes
- Health Score breakdown and change since your last scan
- Multiple vehicles

## Links
- [What Lewis reads, with FAQ](https://www.thelewisapp.com/capabilities/)
- [OBD2 code library](https://www.thelewisapp.com/codes/): plain-English meanings, causes, and repair costs for common check engine codes
- [Blog](https://www.thelewisapp.com/blog)
- [Download](https://www.thelewisapp.com/download)