Solution of Audi p063800 Fault Code

P0638 fault code, applicable to all automobile manufacturers, refers to the control range/performance of throttle actuator. P0638 is the performance of the control range of the throttle actuator. Try cleaning the matching throttle again. The battery must be self-checked for 3 times after power-off matching before it can be started.

In the Electronic Throttle Control (ETC) system, the function of the accelerator pedal position (APP) sensor is to transmit the position of the accelerator pedal to the throttle control module in the form of an electrical signal, which serves as a reference for the throttle actuator to control the throttle opening. The throttle actuator is a stepping motor, which is responsible for controlling the throttle opening according to the instruction of the throttle control module.

This fault code will appear if the electronic control unit (ECU) detects an error in the throttle actuator control circuit. The fault causes include the fault of the throttle position (TP) sensor, the fault of the throttle control module, the fault of the accelerator pedal module and the fault of the electronic control module (PCM or ECM).

Engine fault indicator function:

Used to display the working state of the vehicle engine. When the vehicle starts the self-test, the engine fault indicator lights up. If the engine works normally, it will go out automatically after starting. If the engine fault indicator light stays on after starting, it indicates that the engine may have a mechanical fault. There are many reasons why this fault light is always on, and it is difficult to solve it by self-examination under normal circumstances. It's best to stop the car and have professional maintenance in time.