A Bi-directional Obdii Scan Tool, also known as a bi-directional scanner, goes beyond simply reading diagnostic trouble codes (DTCs) and viewing parameter data. Unlike standard OBD2 scanners, these advanced tools possess the capability of sending commands to various vehicle systems, enabling technicians and DIY mechanics to perform active tests and pinpoint issues more effectively. This two-way communication, often referred to as bi-directional control, actuator tests, or functional tests, allows for in-depth diagnostics and troubleshooting.
Understanding Bi-Directional Control
Bi-directional control facilitates communication between the scan tool and the vehicle’s computer systems. This allows for commands to be sent to specific components, initiating actions like turning on/off relay fans or activating the fuel pump. This active testing capability allows mechanics to observe component behavior in real-time, diagnosing malfunctions that might not be detectable through passive code reading alone. Reprogramming certain modules is also a function of bi-directional control.
For instance, a bi-directional OBDII scan tool can be used to:
- Test Fuel Pump Operation: By commanding the fuel pump on and off, technicians can identify issues with pump pressure, relay functionality, or wiring problems.
- Control Cooling Fans: Activating cooling fans allows for diagnosing issues with fan motors, relays, temperature sensors, and control modules.
- Operate Solenoids: Testing solenoid functionality in various systems, such as emissions, transmission, or ABS, allows for precise diagnosis of component failures.
- Perform System Tests: Many modern vehicles have built-in self-tests that can be initiated through a bi-directional scan tool, providing valuable diagnostic information.
Example of Bi-directional Control: Innova 5610 performing a purge valve diagnosis.
Another Example of Bi-directional Control using the Innova 5610.
Choosing the Right Bi-Directional OBDII Scan Tool
Not all OBDII scan tools offer bi-directional capabilities. When selecting a tool, ensure it specifically supports bi-directional control or active tests. Compatibility with your vehicle’s make, model, and year is also crucial. Consulting vehicle coverage charts provided by scan tool manufacturers is essential to ensure compatibility and access to the necessary bi-directional functions.
Conclusion
A bi-directional OBDII scan tool is an invaluable asset for professional technicians and serious DIYers. Its ability to perform active tests through bi-directional control provides a deeper level of diagnostic capability compared to standard OBDII code readers. By enabling direct interaction with vehicle systems, these tools facilitate faster and more accurate troubleshooting, reducing repair time and ensuring vehicle reliability.
