What is the reason for all the warning lights in a Volkswagen being on?

[McSabrina]

There are several reasons why all the warning lights in a Volkswagen may be on: 1. Bus fault: Modern car dashboards have various indicator lights or alarms under the mask. If all lights are on, it could be due to a CAN bus fault in the ECU or poor contact in the ECU's CAN interface. 2. Excessive dirt: Too much dirt and carbon deposits can cause abnormal air flow, making it difficult to accurately control the normal air intake, leading to unstable gas content and poor engine performance. 3. Low fuel pressure: Low fuel pressure combined with poor constant pressure performance results in a low level of system atomization, making the car difficult to start.