Fuel gage, fuel door, trunk lock, door unlock issues
 

Simulaneously the fuel gage, fuel door unlock, trunk unlock, door unlock in driver's door either work or don't work.I can't find any commonality in the fuse and relays with these functions. Just curious if anyone has any ideas before I take it to a mechanic. Could the problem be identified with a diagnostic check? Thanks in advance.

Are all of those things controlled by a remote fob?

The FOB controls the door and trunk locks only.

So no door locks work when using the switch on the driver's door? Or just the rear door locks?

Sometimes the front doors lock and unlock but the rear doors don't do either. When I'm driving and the fuel gage goes dead I'll hit the door lock switch and they'll lock but won't unlock. And when parked in the driveway if the fuel gage goes dead, I'll check the trunk, doors, fuel door and nothing will unlock. It's like the fuel gage going dead is a signal that none of these things will unlock. Also, when I had frost on the car last week the rear defroster wouldn't work either. But the next day when the fuel gage was working long enough for me to get to work everything was working. There are now periods when these functions are failing for a longer period of time. I assume these things are getting to the point when they won't fail intermittenly and will totally fail.

Sounds like a bad Rear Electronic Module. I think it controls all of these things, but I'd have to double check the wiring diagram.

All the relays and fuses that control these functions are in that panel in the trunk. Sounds like another expensive repair. This my first post on this forum and I really appreciate the replies.

Yep, that's the REM.

UPDATE. It was a loose connection to the REM. The fuel door locking issue was a separate problem. I fixed it by exercising the actuator arm that locks the fuel door and some lubricant.