Which diagnostic tool is commonly used to read trouble codes from vehicle controllers and adapt modules?

• A. A torque wrench
• B. An OBD-II or OEM diagnostic scan tool
• C. A digital multimeter
• D. A thermal camera

Answer: (B)

Diagnosing modern vehicles hinges on a tool that can talk to the car’s control modules and pull fault data. An OBD-II scan tool (or the vehicle manufacturer’s OEM diagnostic tool) is built for this purpose: it retrieves diagnostic trouble codes from the ECUs, lets you view live data, and can access adaptations or programming features as needed. This direct access to fault memory and module settings is what makes it the best choice for reading trouble codes and working with adapt modules.

Other tools don’t serve this purpose. A torque wrench measures how tightly fasteners are tightened; it doesn’t interact with the vehicle’s fault memory. A digital multimeter tests electrical values but doesn’t read codes from the controllers. A thermal camera detects heat patterns to spot issues but doesn’t access ECU trouble codes.