Gas Tank Filler Hatch
 

Just had the ignition on my 1988 mercedes 300se replaced do to bad tumblers. Now the filler hatch for the fuel tank will not automatically unlock it self. I have to open the trunk and manually release it. Can you tell me what Happened to cause this?

A vacuum system unlocks the doors, filler cap flap and the trunk so replacing the ignition tumbler should have no effect on the locking system. I suspect that it's a coincidence and that the vacuum line to the filler cap flap is leaking, or that the vacuum pump is malfunctioning.