No subscription needed

Read OBD for free.
No subscription needed.

Fault codes, sensor readings, trips and history on your phone are free. No account or subscription needed. No subscription paywall to dismiss before reading your car.

Paid cloud sync lets your own AI read your saved car data directly. No more sending screenshots.

  • Free on iPhone and Android
  • Needs a Bluetooth LE (BLE) OBD-II adapter. Classic-Bluetooth-only and Wi-Fi adapters are not supported.
  • For OBD-II / EOBD cars: most petrol cars from 2001 and diesels from 2004 in the EU, 1996+ in the US.
Example fault code P0101
“I think my air-flow sensor caught a cold... ”
Sick cartoon red car with thermometer and scarf
Check Engine light on
Example conversation
Your AI assistant
OBD Vault connected
My Check Engine light just turned on! What happened, what does it mean, and can I still drive?
Read your latest synced scan
Fault code P0101 (air-flow sensor)
  • What it means: the air-flow (MAF) sensor reading doesn’t match what the engine expects. Fuel trim is +19.5%, so the engine is adding fuel to compensate.
  • Can you drive? Nothing in this scan looks urgent: no misfire codes, coolant warming up normally. Drive gently, and stop if the light flashes or the engine runs rough.
  • What to check: a cracked intake hose, loose clamp or dirty sensor are common causes. Check those before buying a new sensor.
Keep in mind: general guidance from your saved data, not a confirmed diagnosis.
Illustration only. Real answers come from your AI assistant and depend on the data your car and adapter provide.

How It Works

From the socket under your steering wheel to a plain-language answer in 3 steps.

  1. STEP 01

    Plug in a BLE OBD-II adapter

    Insert an ELM327-compatible Bluetooth Low Energy (BLE) adapter into the diagnostic socket, usually under the steering wheel. Classic-Bluetooth-only and Wi-Fi adapters will not connect.

  2. STEP 02

    Scan with the OBD Vault app

    Read fault codes, live engine sensors and trip statistics on your phone, with short explanations of what each code means. No account needed, and it works offline.

  3. STEP 03

    Ask your AI assistant

    Turn on Cloud Sync and connect OBD Vault to Claude to talk through your saved scans in everyday language. The ChatGPT connector is in review.

What a scan can show

Illustrative values. What your car reports depends on its make, model and year.
Example data
  • Vehicle Speed
    27 km/h
    City driving
  • Engine RPM
    923 rpm
    Warm-up idle
  • Intake Pressure
    39.0 kPa
    Manifold (MAP)
  • Coolant Temp
    32 °C
    Warming up
  • Battery Voltage
    12.1 V
    As reported by the adapter
  • Long-Term Fuel Trim
    +19.5 %
    Engine adding fuel

The App in Action

Screenshots from the OBD Vault app, connected over Bluetooth Low Energy.

  • OBD Vault live data screen with sensor gauges
    Live data

    Live Sensor Gauges

    Speed, RPM, coolant temperature, battery voltage and intake pressure while the engine is running.

  • OBD Vault trip summary screen
    Trips

    Trip Summary & Fuel

    Trips are recorded once you start moving: distance, average and top speed, RPM and estimated fuel economy.

  • OBD Vault fault code scan results
    Diagnostics

    Fault Codes Explained

    Stored and pending fault codes, the sensor snapshot saved when a fault appeared, and emissions readiness checks.

  • OBD Vault diagnostics screen for a Citroën C2
    Your car

    Standard OBD-II Data

    Generic fault codes and live data on OBD-II / EOBD cars of any make. Some Peugeot and Citroën engines also show a few extra manufacturer readings.

OFFICIAL RELEASE

Read OBD for free

Fault codes, sensor readings, trips and history on your phone are free. No account or subscription needed. Paid cloud sync lets your own AI read your saved car data directly. No more sending screenshots.

  • Free offline diagnostics
  • Optional AI connection over MCP
QR code to install OBD Vault from the App Store
iOS (App Store)
QR code to install OBD Vault from Google Play
Android (Google Play)

Simple Pricing

OBD readings and history on your phone are free. No account or subscription needed. Optional paid cloud sync lets your own AI read your saved data without sending screenshots.

Read OBD for free

No subscription needed
€0 free
  • Read fault codes, freeze-frame data and readiness checks
  • Clear fault codes, with a confirmation step
  • Live sensor gauges and trip recording
  • Your data stays on your phone and works offline
  • No subscription needed
  • No subscription paywall to dismiss before reading your car.

Connect Your AI Assistant

Your own assistant, such as Claude or another MCP client, reads your synced scans directly. No screenshots to send or readings to copy. OBD Vault has no built-in AI.

Set up in Claude

  1. In the OBD Vault app, sign in, subscribe to Cloud Sync & AI Connect and sync your scans.
  2. In Claude, open the connector settings and add OBD Vault. If you add it as a custom connector, use this address: https://mcp.obd-vault.com/mcp
  3. Sign in with your OBD Vault account and allow access to your diagnostics.
  4. Ask Claude to list your vehicles, then ask what your latest scan means.

The connector is accepted for Claude. The ChatGPT connector is in review and not available yet. Read the full connection guide.

Technical details

Saved on your phone

Fault codes, sensor readings, trips and history on your phone are free. No account or subscription needed.

Supported adapters

ELM327-compatible Bluetooth Low Energy (BLE) adapters only. The app finds the adapter’s BLE channels automatically. Bluetooth Classic-only and Wi-Fi adapters are not supported. Adapter quality varies and no specific model is certified yet, so if yours will not connect, tell us.

Vehicle coverage

Standard OBD-II / EOBD diagnostics: stored, pending and permanent fault codes, freeze frames, readiness monitors and the live data your engine computer reports. The adapter detects the vehicle protocol automatically. Extra manufacturer-specific readings are currently decoded for some Peugeot / Citroën (PSA) engines only.

Model Context Protocol

The MCP server uses OAuth sign-in and exposes eleven tools: ten read-only tools for your vehicles, scans, fault codes and trips, plus an on-demand data export. It reads synced records only. It cannot read live data from your phone, send commands to your car or clear codes.