Unlock the car doors and then the gas door is unlocked
The 1985 Mercedes 380 SE has a gas door release latch located on the driver's side floor board near the hood release lever. If the gas door release latch is no longer operable, the cable to the door might be broken.
The "gas door" is magnetically interlocked to the door latches. The door can be readily opened manually when the doors are unlocked.
Same answer as this question.How_do_you_release_the_fuel_door_on_a_1992_Mercedes_300E
The lock for the access door for the gas cap is part of the lock system for the doors. If the car doors are locked the fuel door is locked also. Unlock the doors and the fuel door is unlocked also.
Push on the side of the gas door towards the front of the car and it will pop open.
The fuel tank lock is tied into the vacuum door lock system. When the doors are unlocked then so should the trunk and gas cap. The door lock can be released from inside the trunk.
You just push on it to open it. If the car is locked, the gas door will be locked also. The car needs to be unlocked in order to open the gas filler door.
There is no such thing as a 1998 190E, BTW - It was replaced by the C-class in 1993... On my Mercedes (1984) there is no cap lock, when you lock or unlock the doors, the gas latch (door) is locked or unlocked automatically.
PUSH ON THE DOOR TO RELEASE THEN PULL OPEN
There is no such switch you have to pull it carefully everytime you are about to pump gas
Push in gas cap door it will release