Lexus ES hybrid no start

The symptoms you describe are concerning, especially given the vehicle's age. While an ECU failure is possible, it is less common than other potential issues. Have you inspected the battery cable connections to ensure they are clean and securely fastened? A loose or corroded connection can prevent sufficient current from reaching the starter motor, resulting in a no-start condition. Also, has there been any recent work done on the car?

Thanks for the quick reply! I did a quick visual check of the battery connections, and they seemed okay, but I didn't actually disconnect them and clean them. Is it really possible for a slightly loose connection to cause a complete no-start? Also, no recent work has been done on the car. It just happened out of the blue.

Indeed, even a seemingly minor issue with the battery cable connections can lead to a complete failure to start. The high current demand of the starter motor requires a robust and uninterrupted electrical path. Given that you have ruled out other obvious causes, I would strongly advise a thorough cleaning and tightening of these connections. Should the issue persist after this, a comprehensive diagnostic assessment by a qualified technician is recommended to pinpoint the root cause.

It was the battery cable connections! I cleaned them, and it fired right up. Apparently, they were corroded just enough to cause problems. The car runs again. Cost me 155€ to have it checked. Thanks for the advice!