Its Called The convience feature. Came out about ealry 1992 I believe. Fadi My 500E is having the same problem. You have a leak in the central locking system somewhere. Do you have a after market but factory installed infared. Your saying in the door handle there is a red and green LED. I never saw that on a 500E. I know all the luxury S classes came with that.

When I lock my car intermitently from the drivers door key on or engine running only the drivers door locks. Sometimes when I wait a while till the Central locking system pump stops runing then it will lock all doors. Next time you start your car push down the drivers door knob observe and listen see if you hear a pump running on for about 30-40 seconds. If you do wait till it stops I bet you'll be able to lock all the doors after that.

Thats whats going on with mine hope this helps.


Guido

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500E Sold
2006 Mini Cooper S
Modified,pulley,injectors,suspension
2009 E350 Sport AMG package