My driver side door lock will not lock automatically when using the remote or power lock switch. It will go down manually, but I don't want to keep pushing it down and pulling it up.

While driving, the ML continues to try to automatically lock all of the doors. Is this because of the driver side lock issue? I have to say, yes. Because when I push the lock down manually it stops trying to lock while driving.

Is this a simple fix? Any recommendation of what parts are needed to order? Approximately how many hours should a mechanic charge to fix this?

Thank you kindly!