A 2008 Peugeot 307 car with a mileage of about 40 thousand km. Users reflect: the vehicle suddenly flameout during the driving, after each starting vehicle, the engine can run, but quickly extinguished, window lifting, headlamp control function failure, symptoms similar to the engine was killed lock. After receiving the vehicle, turn on the ignition switch, and the anti-theft indicator light is lit and then extinguished. The diagnostic system is used for self diagnosis. The engine is prohibited from starting system without fault code. The voltage of the battery was measured to 11. 2V. Try to start the vehicle without any reaction. The engine is driven directly, and the engine is running, but it can not accelerate, and it goes out after about ten seconds. After starting, it is confirmed that all the functions of the intelligent control box control (the function of the wiper, the glass elevator and so on) are all normal, indicating that the intelligent control box itself has no problem, only the battery voltage is too low and the power saving mode is enabled.