Free OBD2 Code Reader & DTC Lookup Tool

Instantly decode car diagnostic trouble codes (DTCs) and understand what your check engine light means. Get professional repair advice, cost estimates, and DIY solutions for common automotive problems.

🔍 Free OBD2 Scanner 💡 Instant Code Lookup 🛠️ Repair Guidance

Don't have your fault code? Most auto parts stores like AutoZone, O'Reilly, and Advance Auto will scan your car's computer for free to retrieve OBD2 codes.

Professional OBD2 Scanner & Car Diagnostic Tool

Connect an ELM327 Bluetooth OBD2 adapter for advanced car diagnostics, real-time engine data monitoring, and professional automotive troubleshooting capabilities.

📊 Live Engine Data 🔄 Real-time OBD2 Monitoring 🧹 Clear Check Engine Codes

Status: Ready to Connect

🛡️ Remember to never use this app while driving.

Additional DTC Resources

Need more help with diagnostic trouble codes? Here are additional resources and tools.

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Common Codes

Browse the most frequently encountered fault codes and their meanings.

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Code Categories

Learn about different DTC categories: P (Powertrain), B (Body), C (Chassis), U (Network).

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Repair Guides

Step-by-step repair instructions for DIY-friendly fault codes.

Need Another Lookup?

How It Works

Using OBDWhiz is simple. Follow these three steps to start diagnosing your vehicle like a pro.

1

Connect Adapter

Plug a compatible OBD-II Bluetooth adapter into your vehicle's OBD-II port.

2

Pair with App

Open OBDWhiz and tap "Connect to Vehicle" to pair with your adapter via Bluetooth.

3

View Diagnostics

Instantly see fault codes, real-time data, and vehicle information on your screen.

Features

OBDWhiz is packed with powerful features to make car maintenance easier for everyone.

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Code Reading

Read and clear Diagnostic Trouble Codes (DTCs) with ease.

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Live Data

Monitor real-time sensor data from your vehicle's ECU.

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Cloud Sync

Sync your diagnostic reports across multiple devices.

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DIY Friendly

Get detailed code descriptions and repair advice.

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PWA Support

Install on any device for a native app-like experience.

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Privacy First

Your data is your own. We don't store your vehicle information.

Frequently Asked Questions

Have questions? We've got answers. Here are some of the most common questions we get.

OBD-II (On-Board Diagnostics II) is a standardized system that all cars and light trucks manufactured since 1996 are equipped with. It monitors the vehicle's key engine and emissions components. You need an OBD-II scanner to access this system and read the Diagnostic Trouble Codes (DTCs) it stores when it detects a problem.

OBDWhiz works with most ELM327-based Bluetooth Low Energy (BLE) adapters. These are widely available and affordable. We recommend looking for a reputable brand to ensure reliable connectivity and data transmission.

OBD2 diagnostic trouble codes are categorized by their first letter prefix:

  • P-Codes (Powertrain): Engine, transmission, and emissions system problems. Most common codes like P0420 (catalytic converter) or P0301 (cylinder misfire).
  • B-Codes (Body): Issues with airbags, seatbelts, power windows, door locks, and interior electronics.
  • C-Codes (Chassis): Problems with braking systems, steering, suspension, and wheel speed sensors.
  • U-Codes (Network/Communication): Communication errors between different vehicle modules and control units.

P-codes are the most frequently encountered, especially when the check engine light is on.

Yes, the core features of OBDWhiz, including reading and clearing fault codes and viewing real-time data, are completely free. We believe everyone should have access to this important information about their vehicle.

OBDWhiz is a Progressive Web App (PWA), which means it runs in your web browser. It works on any modern smartphone, tablet, or computer with a browser that supports Web Bluetooth, such as Chrome, Edge, or Opera. No app store download is required.

Apple restricts Web Bluetooth access on iOS and iPadOS for security reasons. Safari and all other browsers on iOS (including Chrome and Firefox) cannot access Bluetooth devices through web pages. This is an Apple platform limitation, not a limitation of OBDWhiz. To use OBD diagnostics on iPhone/iPad, you'll need to download a native app from the App Store or use our desktop bridge feature to relay data from a computer to your iOS device.