Nissan Livina cannot start

Q: A Nissan Livina that I received for repair cannot start its engine. The electronic control system has fault codes for the throttle position sensor and the accelerator pedal position sensor. After replacing these two sensors, the vehicle still cannot start, and the electronic control system cannot communicate. How should this vehicle be repaired?

A: You can disconnect a sensor, such as the water temperature sensor, and use a digital multimeter with a DC 20V setting to measure the 5V power supply voltage of the sensor. Based on experience, it is possible that there is no 5V power supply. While maintaining the measurement state, unplug other sensors to find the short-circuited sensor, such as unplugging the plug of the air-conditioning pressure sensor that is prone to short-circuiting. If the voltage returns to 5V, replace the air-conditioning pressure sensor to eliminate the fault.