I have a 1992 300SE, When I point the infared key at a door or the trunk, I get the proper light notification but the doors don't unlock or lock. The button on the drivers side door dosen't operate either. The trunk closure mechnism isn't functioning. I looked in the trunk fuse box and in the engine compartment fuse box to see if a fuse was blown, everything looked ok. This problem started all at once. Is there something else I need to check?

This is a pneumatic system & there is a pump under the rear seat.
Make sure that fuses # 3 & 11 in the trunk are OK.
Do any other functions of this system work?? ie; chrome handle on trunk, back-up antennas, fold-down rear headrests, or lumbar seats control??

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