What are the main reasons why an Audi A4 won't start?

[LylaAnn]

Audi A4's failure to start is generally caused by issues in the electrical system and air-fuel mixture concentration. Whether the battery needs replacement, whether there are misfires in the spark plugs or ignition coils, whether signals from various sensors are normal, whether carbon buildup is severe, whether fuel pump pressure is insufficient, and whether the throttle body or fuel injectors need cleaning—all these can lead to starting difficulties. Below are some specific reasons that may cause an Audi A4 to fail to start: 1. The engine does not reach the required RPM. 2. No power transmission is detected, meaning no P/N signal or no connection. 3. Battery voltage is below the minimum threshold. 4. Mechanical transmission of the engine is obstructed. 5. The number of failed start attempts exceeds the critical value. 6. The engine start interruption time is exceeded.