Is it normal for the engine light to come on after powering on the car?
2 Answers
It is normal for the fault light to come on after powering on the car. Here are the extended details: 1. During the power-on self-check, three fault lights will illuminate: the engine emission fault light, the oil pressure light, and the car voltage fault light. These three lights will automatically turn off after lighting up. 2. The reason the lights come on is that the engine is not started, and the oxygen sensor cannot detect normal exhaust, so the light turns on. 3. The oil pump is driven by the engine. If the engine is not running, there is no oil pressure, hence the light. 4. The generator is also driven by the engine. If the engine is not running, there is no electrical output, which will also trigger an alarm light. 5. The battery symbol only indicates insufficient voltage in the generator circuit and does not detect the battery. As long as these lights turn off after the engine starts, it is considered normal.
When the car is powered on, the engine light illuminating is usually normal—it briefly lights up for a few seconds during the system's pre-start self-test to check functionality. If the light turns off quickly, everything is fine. However, if the light stays on or comes on while driving, it indicates potential engine issues, such as a faulty oxygen sensor, clogged intake valves, or loose electrical connections, which can lead to increased fuel consumption or reduced power. In such cases, promptly use the onboard diagnostic port to read the trouble codes and identify the cause—delaying could result in more severe damage. I've seen instances where the light came on during highway driving, and the engine eventually failed, costing thousands to repair. Simply observing the light for a moment during startup can prevent major problems, offering peace of mind. Regular maintenance and sensor checks can also help prevent such warning light issues.
