System and method of malfunction diagnosis of middle door or step for vehicle

A malfunction diagnosis system in a vehicle, the vehicle comprising an engine, a middle door or a step of the vehicle, and an accelerator pedal comprising an interlock, the system comprising:

• one or more controllers configured to perform the following steps:
• a first receiving step of receiving a first operating signal from the middle door or the step of the vehicle;
• a first diagnosis step of diagnosing whether the middle door or the step is in a failure state based on the first operating signal;
• a second receiving step of receiving a second operating signal from the middle door or the step of the vehicle;
• a second diagnosis step of diagnosing whether the middle door or the step is in a failure state based on the second operating signal;
• determining whether an engine is starting if the first and second diagnosis steps indicate that the middle door or the step is in the failure state;
• and
• setting an interlock on an accelerator pedal if it is determined that the engine is starting.