What causes the engine fault yellow light to illuminate in a Mercedes-Benz A200L?

[LeCharlie]

Here are the specific causes and solutions for the engine fault yellow light illuminating in a Mercedes-Benz A200L: 1. Carbon buildup in the vehicle causing ignition difficulties. This may be accompanied by slight shaking at idle; cleaning the throttle body and fuel injectors should resolve the issue. 2. Weak spark plug ignition energy. Failure to replace spark plugs after their maintenance interval leads to severely reduced ignition energy, potentially causing misfires. 3. Insufficient fuel rail low pressure. Low fuel pressure in the low-pressure fuel circuit directly causes secondary ignition in the engine; specifically check the fuel pressure regulator, fuel pump, fuel filter, and internal fuel lines. 4. Weak battery. The solution is to jump-start the vehicle using another car or battery. 5. Incorrect engine timing. Engine timing not matching the engine specifications; replacing the alternator belt on certain engine models may cause timing belt teeth to skip, resulting in ignition difficulties.