Why does the engine malfunction indicator light come on when the car's air conditioning is turned on?
3 Answers
The reasons why the engine malfunction indicator light comes on when the car's air conditioning is turned on are as follows: Sensors: The engine malfunction indicator light will come on when the sensors are damaged, have poor contact, or experience signal interruption. Engine: Poor engine maintenance is the most common cause of the engine malfunction indicator light coming on. Therefore, it is recommended that car owners perform regular maintenance and maintain good driving habits, otherwise it will increase the burden on the engine operation. Poor quality fuel and engine oil: If not added as required, it will cause engine wear over time, leading to the engine malfunction indicator light coming on. Generally, manufacturers will recommend which grade of fuel and which type of engine oil to use.
That day I was driving my family out for fun, and it was so hot that I turned on the air conditioning. Suddenly, the engine malfunction indicator light came on, which made me quite nervous. This issue is actually quite common. Turning on the AC increases the load and may cause sensors to falsely report faults, such as oxygen sensor detection mismatches or problems with the AC compressor getting stuck. It could also be due to excessive electrical load blowing a fuse, especially in older cars with aging wiring. Starting the AC when the battery is low on charge can also be a trigger. At the time, I noticed the engine sounded a bit odd, so I quickly turned off the AC, pulled over, and checked the engine. To be safe, I later went to a repair shop to read the fault code, which revealed that the AC control valve was stuck. My advice is not to continue driving if you encounter a similar situation and to get it checked early to avoid damaging the engine. Regularly cleaning the AC filter and maintaining the electrical system can help reduce the risk.
I drive an ordinary family car, and last month the same issue troubled me for a long time. While driving with the air conditioning on, the engine light would come on. At first, I thought it was just my imagination. Later, I figured out that this usually happens because turning on the AC increases the engine load, and the system detects an anomaly, triggering the warning light. Common causes include a worn-out AC compressor that stops working, short circuits burning the connectors, or faulty sensors like those in the cooling system reporting errors. I tried checking it myself: turning off the AC to see if the light went off, then opening the hood to listen for unusual noises, and checking the battery level. Most of the time, it's a minor issue, but that time I found out it was a loose compressor belt. I fixed it in time and even saved some money. I shared this with my friends, and they found it very practical. Developing a habit of regular maintenance for AC components can help avoid such embarrassing situations while driving.
