Why Does the Car Suddenly Lose Power and the Malfunction Light Come On?
4 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.
I've been driving an old car for years and recently encountered an issue where the car wouldn't accelerate and the warning light came on, as if the engine had gone on strike. It could be a faulty fuel pump causing an interruption in fuel supply, or a dirty air flow meter sending incorrect data to the ECU, leading to fuel restriction. Electrical issues like a blown fuse or a shorted ignition coil could also be the cause. At low speeds, it's manageable, but it becomes extremely dangerous when turning, so you must pull over and check. Don't randomly poke at the wiring yourself; first, check if the fuel tank has enough gas as a simple troubleshooting step. Eventually, I took the car to a small repair shop, and the mechanic said replacing the fuel pump fixed the issue. Remember, don't delay maintenance—engine health is the cornerstone of safe driving.
I think there are three main reasons why a car doesn't respond when accelerating and the fault light is on: First, a fuel system malfunction, such as a failed fuel pump or clogged filter screen; Second, sensor issues, like an oxygen sensor misreading causing the ECU to cut fuel supply; Third, ignition components such as faulty spark plugs leading to insufficient power. Try restarting the engine—it might work temporarily. But safety comes first, pull over, turn off the engine, and check for fuel leaks or unusual noises. Have it towed to a repair shop as soon as possible for diagnosis and repairs to eliminate potential hazards.
