A modern Beijing ix35 car with a mileage of about 63 thousand km in 2011. User response: the vehicle sometimes intermittently flameout, the engine fault indicator lights up, and the engine is restarted after the fire is stopped, which can not speed up. Fault diagnosis: connect the Beijing modern factory diagnostic instrument HI-DS to read the fault code of the engine system, and find 4 fault codes. (1) P0123 throttle valve position sensor. P2106 ETS CONT-FOR C. LIMITEDP. (3) P0222 throttle position sensor B - low signal voltage. P2110 ETS is forced to limit the speed. The diagnostic code is used to clear the fault code program, and it can be cleared. But once the engine is started, the fault indicator light is on. The electronic control throttle control (ETC) system consists of the throttle body, the throttle position sensor (TPS) 1 and the throttle position sensor (TPS) 2, the accelerator pedal position sensor (APS) 1 and the acceleration pedal position sensor (APS) 2. The same power supply voltage is shared by the TPS 1 and the TPS 2. The throttle motor is controlled by the throttle motor, and the throttle motor is controlled by the engine control module (PCM). The opposite position indicator shows the characteristics of the reverse signal. After starting, the output voltage of TPS 1 increases steadily with the throttle opening. The output voltage of TPS 2 decreases steadily with the throttle opening. TPS provides feedback information to PCM, controls throttle motor, so as to properly control throttle opening and respond to driving state. If a fault occurs within the electronic control throttle control (ETC) system, the PCM can stop the engine work when the predetermined data stored in the memory is controlled by the engine or is expected to be safe, as an emergency operation (failure protection) mode. The purpose of failure protection mode is to control the engine as far as possible when it fails. PCM records the fault code when recording the fault code associated with the ETC system. This fault code only indicates faults related to the ETC system and the engine is in failure protection mode. Repair all failures associated with the ETC system. Find the maintenance manual, found that P0123, P2106, P0222, P2110 are all the same fault, the throttle is not found abnormal phenomenon, pull the plug in the maintenance manual to check the throttle plug power and grounding, are in the normal range, suspect the throttle is broken lead to the fault lights. I replaced the throttle by replacing the throttle, after replacing the fault code, starting the engine, all normal, the engine fault indicator lights out, after the test no longer intermittently extinguished, troubleshooting. Troubleshooting: replace throttle assembly and troubleshooting. Maintenance summary: maintenance personnel failed to make full use of data analysis and replacement when initially diagnosing the vehicle malfunction. Therefore, paying attention to standardized maintenance is a real effective way to improve the efficiency and quality of maintenance and improve the quality of maintenance personnel. In addition, catching the details of each maintenance is the key to finding fault spots accurately. I suggest that the maintenance personnel make full use of special diagnostic tools, choose appropriate data, solve difficult problems, improve the technical level, and use the users' satisfaction, and improve their ability.