There’s no Code requirement for any door in a house, except there must be one main door that needs to be 36” in width.
However, as @Doug Deden has explained, there could be a requirement for air intake or exhaust in order for your equipment to operate properly.
You could check to see if the door louvres are using air by thumb tacking some paper over the louvres and see if the paper moves in or out.
Edit: Ooops...I goofed. There needs to be one exit door in each unit that is 36” wide. (I said 32”.) Also if there is a door between the garage and house it needs to be a solid core door or fire rated. Also, the exit door needs to be side swinging and be able to be opened without special knowledge. (A sliding door does not comply.) There is no other width requirement, including width into the restroom. (See ICC R311.4)