How to manually reset the car malfunction indicator light?
2 Answers
Regardless of the reason causing the engine malfunction light to illuminate, after troubleshooting, it is necessary to use a computer to access the ECU program for resetting. There is no manual method to reset the malfunction light. The reasons for the engine malfunction light to illuminate are as follows: 1. Poor quality gasoline that does not meet standards. This occurs when low-quality gasoline is added at non-standard gas stations, leading to incomplete combustion of the air-fuel mixture during engine operation, which triggers the engine malfunction light. This does not affect driving safety but may cause some degree of damage to the engine. 2. Oxygen sensor failure. Modern cars are equipped with two oxygen sensors, one before and one after the three-way catalytic converter. The front oxygen sensor's function is to detect the air-fuel ratio under different engine operating conditions, while the ECU uses this signal to adjust fuel injection and calculate ignition timing.
I've fixed my car many times myself. To turn off the check engine light, you can start by using an OBD scanner tool—plug it into the car's port, usually located under the steering wheel, and clear the trouble codes. If you don't have a tool, try disconnecting the negative battery cable for five to ten minutes and then reconnecting it to reset the system. However, these are temporary fixes—the light comes on because the computer detects an issue, such as a faulty sensor or emission problem. If you don’t address the root cause, the light will come back on soon. I once had the light turn on due to low engine oil, and it only stayed off after topping it up and clearing the code. For safety, before attempting manual fixes, check simple things like oil pressure to avoid major risks. It's best to first check the manual or look up model-specific methods online for a safer approach. If all else fails, head to a professional shop right away.
