c4link

Turn your smartphone into a powerful vehicle diagnostics center.

Built for Car People

Whether you drive a classic muscle car, lifted truck, turbo import, European performance car, daily commuter, or track machine, C4Link helps you keep your vehicle healthy and performing at its best.

One Plug. One App. Total Vehicle Insight.

C4Link.app
Connect. Diagnose. Drive Smarter.

Turn your smartphone into a powerful vehicle diagnostics center.

C4Link pairs a high-speed Bluetooth OBD-II adapter with the C4Link.app to give you professional-grade vehicle insights in seconds. Whether you're a daily driver, weekend enthusiast, DIY mechanic, or performance builder, C4Link helps you understand exactly what's happening under the hood

features

🚗 Real-Time Live Data

Watch your vehicle come alive with live sensor readings including:

  • Engine RPM

  • Vehicle Speed

  • Coolant Temperature

  • Intake Air Temperature

  • Oil Temperature*

  • Oil Pressure*

  • Boost / Turbo Pressure*

  • Throttle Position

  • Fuel Pressure

  • Fuel Trim

  • Air/Fuel Ratio

  • MAF & MAP Sensors

  • Ignition Timing

  • O2 Sensor Data

  • Battery Voltage

  • Charging System Status

  • Transmission Temperature*

  • DPF & Emissions Data*

  • Hundreds of additional manufacturer-supported sensors

*Vehicle dependent.

📈 Data Logging

Record every drive.

  • Save live sensor data

  • Export CSV logs

  • Share with your tuner or mechanic

  • Compare runs

  • Analyze performance over time

🏁 Performance Tools

Built for enthusiasts.

  • 0–60 MPH Timer

  • 60–130 MPH Timer

  • Quarter Mile Timer

  • Lap Timer

  • Acceleration Graphs

  • G-Force Meter

  • Performance History

🚘 Garage

Manage all of your vehicles in one place.

Store:

  • VIN Information

  • Service Records

  • Maintenance History

  • Diagnostic Reports

  • Modifications

  • Photos

  • Insurance Information

  • Mileage History

🔧 Full Vehicle Diagnostics

Know what's wrong before visiting the repair shop.

  • Read Check Engine (CEL) Codes

  • Clear Diagnostic Trouble Codes

  • View Code Definitions

  • Freeze Frame Data

  • Pending Codes

  • Permanent Codes

  • Emissions Readiness Status

🚨 Advanced System Scanning

Go beyond the engine.

Scan supported modules including:

  • ABS

  • Airbag / SRS

  • Transmission

  • Steering

  • Body Control Module

  • TPMS

  • AWD / 4WD Systems

  • Hybrid & EV Systems

  • Manufacturer-Specific Modules

❤️ Vehicle Health Score

Get an instant snapshot of your vehicle's overall condition.

C4Link analyzes diagnostic data and generates an easy-to-understand health score, helping you catch issues before they become expensive repairs.

📊 Live Digital Dashboard

Customize beautiful gauges for:

  • Boost

  • RPM

  • Speed

  • Coolant Temp

  • Oil Temp

  • Battery Voltage

  • AFR

  • Transmission Temp

  • Horsepower Estimates

  • Torque Estimates

Choose from multiple dashboard themes designed for both street and performance vehicles.

🔔 Smart Maintenance

Never miss important service intervals.

Track:

  • Oil Changes

  • Tire Rotations

  • Brake Service

  • Transmission Fluid

  • Coolant Flushes

  • Spark Plugs

  • Air Filters

  • Custom Maintenance Reminders

⛽ Fuel Economy Tracking

Monitor:

  • MPG

  • Fuel Consumption

  • Trip Cost

  • Distance Per Tank

  • Fuel History