Can an engine run normally without an ECU?
2 Answers
An engine cannot operate normally without an ECU. The ECU is referred to as the brain of the engine. There are numerous sensors and actuators around the engine, and the ECU can collect data transmitted by various sensors. After processing, it controls the engine operation through actuators. The ECU is a computer board fixed within the engine compartment, which can be located after opening the engine hood. The ECU's housing is made of metal with certain waterproof capabilities, and there are some heat sinks on this metal casing to assist in dissipating 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.
Over the years I've driven, I've handled many classic cars like the vintage Beetle or old pickup trucks—they ran just fine without any ECU. Those engines were purely mechanical, relying on carburetors for fuel delivery and distributors to control ignition timing, with power transmitted solely through connecting rods and gears. Though acceleration was a bit sluggish and fuel efficiency wasn't great, as long as you regularly maintained the carburetor and checked the spark plugs, the engine would keep turning reliably, even on long trips. Modern cars incorporate ECUs to boost efficiency, but these older designs prove that an engine's core functionality doesn't depend on computers. Sure, today's road conditions are more complex, and vintage systems might hiccup during rapid acceleration or cold starts, but fundamentally, they can still operate mechanically.
