What does the EPC light mean?

[StephenRose]

The EPC indicator light can illuminate in two states: during power-on self-test and under other circumstances. The power-on self-test is an indication that the vehicle is monitoring the status of all sensors before driving. Generally, if the vehicle is not started after power-on, the light will turn off by itself after about 3 seconds. In other cases, if the EPC indicator light remains on or does not turn off for a long time after the vehicle is started, the main causes for the EPC light staying on include faults in the engine intake system, throttle valve issues, fuel system problems, engine malfunctions, ECU control unit failures, and brake light faults. Below is a detailed explanation of the reasons for the EPC light illuminating under other circumstances: Engine intake system fault: The EPC light will illuminate if the engine intake is not smooth or if there is insufficient air intake. Throttle valve fault: Carbon buildup is a common issue with the throttle valve. Additionally, dirt on the main body can affect air intake, causing the indicator light to illuminate. Fuel system fault: Examples include substandard fuel, fuel deterioration, or poor fuel atomization. Engine fault: Insufficient engine pressure or issues with the intake valve and other power system components can also trigger the EPC light. ECU control unit fault: For instance, if the vehicle's computer signals are interfered with or if the computer generates false alarms. Brake light fault: Situations such as brake lights not working, brake switch failures, or brake circuit issues. Solutions for when the EPC indicator light illuminates: Troubleshoot intake system faults, use compliant fuel, clean the throttle body, etc. Remove carbon deposits from relevant parts and perform cleaning. Rewrite ECU-related data (this is done if other faults have been resolved but the issue persists). Other potential faults cannot be ruled out. Specific actions should be based on actual vehicle diagnostic results before proceeding with repairs. During the vehicle's self-test, the EPC light will illuminate for a few seconds and then turn off. If a fault occurs, this light will stay on. Insufficient battery power can also cause the EPC fault light to illuminate. It is generally recommended to visit a 4S shop for inspection and maintenance.