What happened to the throttle failure after Audi 2.4 changed the valve body?

Audi 2.4 After replacing the valve body, the throttle valve does not work for the following reasons:

1. The failure of the engine control unit will cause the throttle valve not to work.

2. The throttle motor is damaged, and the circuit of the throttle servo motor has poor contact.

3. Too much carbon deposit in the throttle will cause the throttle to be ineffective.