What is the fourth of the nine general steps for diagnosing automatic engine shutdown faults?

Before diagnosing an engine automatic stall fault, safety must first be ensured: stop the vehicle and apply the parking brake, then open the hood and make sure the engine is cold. Check fault codes: use a diagnostic tool or OBD scanner connected to the vehicle's diagnostic port to read fault codes. Fault codes can provide clues about the cause of the stall. Check the fuel system: check whether the fuel pump, fuel filter, and fuel injectors are working properly, and make sure the fuel supply is sufficient and there are no blockages or leaks. Check the ignition system: check whether the ignition coils, spark plugs, and ignition wires are working properly, make sure the spark plug gap is correct, and ensure there are no electrical faults in the ignition system. Check the power circuits and sensor connections: check whether the power circuits of the engine control unit (ECU) are properly connected, and also check the connections of sensors such as the oxygen sensor and throttle sensor. Check the air flow sensor: a faulty air flow sensor may cause the engine to stall. The operating condition of the sensor should be checked to make sure it is not contaminated or damaged. Check the exhaust system: check whether the exhaust pipe is blocked and whether the exhaust valve is working properly. Problems in the exhaust system may also cause the engine to stall. Check the cooling system: make sure the coolant level is normal and that the cooling system has no leaks or faults, so as to avoid engine stall caused by overheating. Check the transmission system: transmission system faults, such as clutch problems or transmission failure, may also cause the engine to stall. The operating condition of the transmission system should be checked to make sure there are no faults. Perform a comprehensive analysis: conduct a comprehensive analysis based on the previous inspection results to identify the possible cause of the stall. If the cause cannot be determined, further inspection or consultation with a professional technician may be required.