Can a car run normally without an ECU?
2 Answers
Without an ECU, a car cannot run normally. The ECU is known as the brain of the engine. There are many sensors and actuators around the engine, and the ECU can collect data from various sensors. After processing, it can control the engine operation through the actuators. The ECU is a computer board fixed in the engine compartment, which can be found after opening the engine hood. The ECU's metal casing has certain waterproof properties and is equipped with heat sinks to help dissipate heat. When washing the car, avoid directly spraying water into the engine compartment with a hose, as this may damage the ECU and electronic sensors inside the engine compartment.
I find this question quite interesting because I've driven some older cars, like my dad's 1970s Ford. That car ran purely on a carburetor and mechanical components—no ECU whatsoever. You had to manually turn the key to start it, and while the engine sounded rough after firing up, it could still drive normally. Modern cars are different, though. The ECU controls engine ignition, fuel injection, and emission systems. Without it, the engine can't properly adjust the air-fuel mixture, potentially failing to start or running so roughly it feels like an earthquake. Even if you manage to start it, fuel consumption would skyrocket, emissions would exceed limits (making it environmentally unfriendly), and safety risks would arise—like failed engine overheat protection leading to breakdowns. Simply put, older cars could limp along without an ECU, but modern ones would be practically useless without it, requiring immediate repair to avoid stalling or accidents on the road.
