What Lewis reads from your car
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.
From your car
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.
What Lewis does with it
AI scan analysisPro
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 LewisPro
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 inspectionPro
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.
Makes with manufacturer-specific data
Manufacturer-specific live data is available on these 35 makes, and module-by-module codes on most of them. Standard codes and live data work on any OBD2 car.
- 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.
Scanners
On iPhone, Lewis works with Bluetooth LE (BLE) OBD2 scanners and the OBDLink MX+.
Free and Lewis Pro
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
Questions
Can Lewis tell me what a repair should cost?
Yes. With Lewis Pro, ask Lewis about a code or a problem and it gives you an estimated repair cost range for your car. Pre-purchase inspections also include estimated repair costs for everything the scan finds. Estimates are a guide, and actual shop prices vary.
What does Lewis read from my car?
Lewis reads stored and pending trouble codes from your car's engine and emissions computers, plus standard live data such as RPM, temperatures, throttle, engine load, and fuel trims. On most of the 35 makes we support, it also reads codes from the transmission, hybrid battery, and other powertrain computers module by module. With Lewis Pro it reads manufacturer-specific live data on all 35 makes.
Which cars does Lewis work with?
Lewis works with cars that have an OBD2 port. Standard codes and live data work on any OBD2 car. Manufacturer-specific live data is available on 35 makes, and module-by-module codes on most of them: 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.
Which OBD2 scanner do I need?
On iPhone, Lewis works with Bluetooth LE (BLE) OBD2 scanners and the OBDLink MX+. Lewis checks your scanner when you connect and tells you if it could not reach part of your car.
What is free and what is in Lewis Pro?
Free includes unlimited scans, trouble codes with descriptions and severity, the Health Score, standard live data, recall checks, and one vehicle. Lewis Pro adds AI scan analysis, chat with Lewis including estimated repair costs, pre-purchase inspections, manufacturer-specific live data on 35 makes, a Health Score breakdown, and multiple vehicles.
Do I need my VIN for the recall check?
No. Lewis checks NHTSA safety recall campaigns by year, make, and model, so no VIN or scanner is needed.
What does the pre-purchase inspection include?
Lewis runs its full scan on the car you are considering, then gives you a Buy, Buy with caution, or Walk away verdict, the codes it found with the module each came from, estimated repair cost ranges, and a negotiation script. If you enter the asking price, it also suggests an opening offer, a floor, and a ceiling. Pre-purchase inspections are part of Lewis Pro.
Can I try Lewis before I connect a scanner?
Yes. Demo mode lets you explore Lewis with a sample vehicle, and the recall check works without a scanner.