Why Does the Car Suddenly Lose Power and the Malfunction Light Come On?
2 Answers
It is likely due to a throttle position sensor malfunction. Below are the reasons why a car suddenly loses power and the malfunction light comes on: 1. The idle switch is short-circuited or open-circuited. 2. The throttle position sensor is improperly installed or adjusted, causing the idle switch not to close when the throttle is fully closed, or the idle switch remains closed even when the throttle is partially open. 3. Poor contact of the sliding contact in the linear variable resistor, resulting in intermittent signal interruption from the throttle position sensor during the throttle's movement from fully closed to fully open. When the throttle position sensor exhibits the above faults, it can lead to abnormal engine idle operation (such as excessively high or low idle speed, unstable idle, or easy stalling) or abnormal engine acceleration (such as engine shaking during acceleration, delayed acceleration response, etc.). Sometimes, it may also cause intermittent engine shaking during operation.
Last time I was driving, the car wouldn't accelerate and the warning light came on, which was really frustrating. I think this is usually caused by a faulty fuel pump failing to supply fuel, or sensors like the oxygen sensor malfunctioning and misleading the ECU to adjust fuel injection. Too much carbon buildup in the throttle body restricting air intake, or worn spark plugs causing poor ignition can also lead to insufficient power. Slow response from electronic throttle bodies or ECU software errors are also common issues. It's even more dangerous on highways—immediately slow down and pull over instead of forcing the accelerator. Checking fuel levels or a simple restart might temporarily help, but ultimately you need to visit a professional shop to read the OBD fault codes for a proper fix. Regular maintenance like changing fuel filters and cleaning the throttle body can help prevent these problems.
