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What is Bi-Directional?

By R&D
Published on December 20th, 2023

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To explain what Bi-Directional controls mean with scan tools.

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What Is Bi-Directional Control?

In the context of scan tools, bi-directional refers to the ability of the tool to communicate and interact with various vehicle systems in both directions. It means that the scan tool can not only read the diagnostic trouble codes (DTCs) and retrieve data from the vehicle's onboard computer systems but also send commands and perform actions on those systems.

A bi-directional scan tool allows technicians to perform advanced diagnostic functions beyond basic code reading and data retrieval. It enables them to actively test, control, and interact with different components and systems within the vehicle. For example, a bi-directional scan tool can:

  • Actuate components: It can command specific components to operate, such as activating relays, opening or closing valves, or turning on lights. This capability helps technicians diagnose issues related to specific parts of the vehicle.
  • Perform system tests: The tool can initiate system tests or self-tests on various vehicle systems. This includes running tests on the engine, transmission, ABS (anti-lock braking system), airbags, emissions systems, and more. It allows technicians to verify the proper functioning of these systems and identify any faults or malfunctions.
  • Reset or reprogram modules: A bi-directional scan tool can reset certain modules or systems within the vehicle. This can include resetting the service light, recalibrating sensors, or reprogramming control modules with updated software.
  • Adapt or relearn procedures: In some cases, the scan tool can help initiate procedures for system adaptations or relearning processes. For example, it can perform throttle body relearn, idle speed relearn, or steering angle sensor calibration.

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By providing control and interaction capabilities, bi-directional scan tools empower technicians to perform advanced diagnostics, simulate real-world scenarios, and perform necessary adjustments or repairs. However, it's important to note that the availability of bi-directional functionality can vary depending on the specific scan tool and the vehicle's make, model, and year, as not all systems and components may support bi-directional communication.

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