Pic. 2.1 Simple Code Readers - This is an economical way to read DTCs when the CHECK ENGINE warning light comes on (check engine)
2. With the introduction of a legal system in several countries to reduce harmful emissions, known as the on-board diagnostic system (OBD-II), special testers have been developed. Some instrument manufacturers offer OBD II compliant testers for car enthusiasts (pic. 2.2).
Pic. 2.2 Testers like those shown from Actron and AutoXray are powerful diagnostic tools. They can tell you everything you want to know about your engine management system
General description of the OBD-II system
3. All models are equipped with a second-generation on-board diagnostic system (OVP-P). The OBD-II system includes a computer known as the powertrain control module (RSM), information sensors that monitor various engine functions and send data to the PCM, and output actuators that process various control signals from the PCM. The OBD II system also includes a number of diagnostic monitoring functions that detect and identify faults in the fuel injection and emission control systems and store the information in the computer's memory. In addition, the system checks sensors and output actuators, diagnoses driving cycles, outputs freeze frame data, and clears codes.
4. Access to a powerful diagnostic computer such as PCM is possible using an OBD-II tester and a 16-pin data link connector (DLC), located under the dashboard on the driver's side. The PCM is the brains of the electronically controlled fuel and emission control system. It receives data from a network of sensors and other electronic components (switches, relays, etc.). Based on the information received, the PCM generates output signals that allow you to control various relays, solenoid valves (e.g. fuel injectors) and other executive devices. The PCM is specially calibrated to optimize emissions reduction, fuel consumption and overall vehicle drivability.
5. It is not recommended that you diagnose or replace the PCM or the components of the emission reduction systems yourself until the warranty period for the vehicle has expired. Because emissions reduction system components are warranted, any owner-caused damage to the PCM, sensors and/or controls may void the warranty. Therefore, if the PCM or any part of the system is malfunctioning, have the vehicle checked by the dealer's service department.