I. What Causes the OBD System Indicator Light to Illuminate?
The OBD indicator light on a car’s instrument panel represents an engine exhaust system malfunction indicator. Simply put, it means the car’s exhaust emissions are severely exceeding safe levels.
There are many reasons why the OBD light might illuminate, but the main one is an emissions malfunction. Generally, an illuminated OBD light rarely prevents the car from starting; in other words, the car can still be driven. This is the importance of the OBD light. If ignored, it could potentially lead to emissions hundreds of times higher than normal. Therefore, when an exhaust emission malfunction occurs, the OBD light will illuminate to promptly remind the driver to repair the problem as soon as possible.
II. What to Do When the OBD System Indicator Light Illuminates?
How do you clear the OBD light? It’s important to know that the OBD device monitors multiple systems and components, including the engine, catalytic converter, particulate filter, oxygen sensor, emissions control system, fuel system, EGR, etc. Therefore, finding the root cause of the fault to clear the OBD indicator light is somewhat difficult. The simplest method is to read the fault codes using an OBD2 scanner. This is because the OBD connects to the electronic control unit (ECU) through various emissions-related component information, and the ECU has the function of detecting and analyzing emissions-related faults. When an emission fault occurs, the ECU records fault information and related codes. Therefore, by reading the fault codes, we can quickly and accurately determine the nature and location of the fault.
III. Introduction to the OBD System
OBD stands for On-Board Diagnostics. This system monitors the engine control system and other functional modules of the vehicle in real time during operation. If any abnormalities are detected, it uses a specific algorithm to determine the specific fault and stores it in the system’s memory as diagnostic fault codes. The useful information obtained after self-diagnosis can assist in vehicle repair and maintenance. Repair personnel can use original equipment manufacturer (OEM) diagnostic tools to read the fault codes, thereby quickly locating the fault, facilitating vehicle repair, and reducing the time spent on manual diagnosis.