FIRSTOOL V390 OBD2 Scanner Diagnostic Code Reader — Compact OBDII Scanner with I/M Readiness & Battery Test

The FIRSTOOL V390 is a compact OBD2 diagnostic scanner that reads and clears engine codes, checks I/M readiness, tests 12V batteries, and streams live vehicle data for cars and light trucks built after 1996.

Whether you’re a DIYer or a technician, the V390 brings a professional-grade set of diagnostics to a pocket-sized device. It detects generic and manufacturer-specific DTCs, shows freeze-frame and live sensor data, performs I/M smog readiness checks, and includes a simple battery voltage test — all without needing a smartphone app or subscription.

How does the V390 help me identify and clear check engine codes?

The V390 scans your vehicle’s OBD2 system to retrieve stored, pending, and manufacturer-specific fault codes. It displays code definitions from a built-in database so you can understand the likely cause, then lets you clear codes and switch off the Malfunction Indicator Light (MIL) once the issue is addressed.

• Reads generic and manufacturer-specific DTCs
• Built-in 40,000+ code lookup database for quick definitions
• Clears codes and turns off check engine light after repairs
• Shows freeze-frame data to capture conditions when the fault occurred

Can the scanner help me prepare for emissions or smog testing?

The V390 checks the vehicle’s I/M readiness monitors to confirm whether emission-related systems report as "ready." That helps you know in advance if the car is likely to pass a smog inspection or if further driving/repairs are needed to reset monitors.

• One-touch I/M readiness check for emissions status
• Identifies which monitors are incomplete or not ready
• Helps avoid failed smog tests by indicating required steps

What live data and tests does this tool provide?

The device streams real-time sensor values so you can monitor RPM, coolant temperature, vehicle speed, fuel trim, and more. It also includes an EVAP leak test option and a built-in 12V battery voltage check to help diagnose charging and electrical issues quickly.

• Real-time data display of multiple PIDs (rpm, temp, speed, airflow, etc.)
• EVAP leak test and O2 sensor diagnostics available
• 12V battery voltage measurement to assess battery health

Which vehicles and protocols are supported by FIRSTOOL V390?

The V390 works with most OBD2-compliant cars, SUVs, and light trucks: U.S. models from 1996 onward, EU models from 2003, and many Asian vehicles that support OBDII/CAN. It supports common communication standards such as J1850 PWM/VPW, ISO9141, KWP2000, and CAN.

• Compatible with 16-pin OBDII ports and major OBD protocols
• Supports passenger cars, SUVs, and light trucks post-1996
• Multilanguage menu (English, German, Spanish, French, and more)

Who is this for? The FIRSTOOL V390 suits car owners who want clear, immediate diagnostics without subscribing to software, independent mechanics who need a reliable handheld scanner, and anyone preparing for emissions testing or checking battery condition. Its rugged, pocketable design and straightforward menus make it practical for hobbyists and professionals who need fast, on-the-spot answers about vehicle health.