the car sat for maybe 3 weeks. garaged. went to use it today and all i got was a flash of the lights..... but no door locks unlocked. tried the trunk... no dice. tried to take the manual key out of the regular key fob and manually unlock it but that didn't work either! any ideas???? thanks in advance.

- Evan

 

The mechanical key is just that, so I can't think why you can't unlock the drivers door with it.

I suspect that once you gain entry with the mechanical key you will find that you have a dead battery but there are a host of other possibilities but insufficient info to focus on a definitive cause.

Stuart

 

HMMMM........... is it possible that the mechanical key is the wrong key even though the electric fob works? I ask because the key is not the original one.

 

I have the same problem with my s430 doors will not unlock or lock with the fob but i can open the drivers door with the key can some one give me a suggestion to what they think it could be i had a mechanic tell me that the battery behind the seat could be dead and it will cost about a 1000 dollars, once i get in the car it starts with no problem but the doors will not lock unless i do it manually

 

@1Marshay. Your problem is different.

You likely need a new PSE unit which is "behind the seat" and is expensive but the cost you quote looks unreasonable...but I have no real idea of prices in the USA,.
Lots of posts on no locking. Look under SLK since the problem is most prevalent on that model.

@Ed1655

The mechanical key "unlocks" the single door into which it is inserted. I assume that once in the lock it turns 1/4 turn or so like a normal lock. If it won't turn then the lock is seized or it is the wrong key.
However this action doesn't unlatch the door. You need to use the door handle to do this as usual.
No need to coordinate both at exactly the same time etc.
If the mechanical lock doesn't work after turning 1/4 turn or so then this is extremely unlikelty (although not totally impossible) to have occurred at the same time as your pneumatic failure on all doors.
I suspect that if the symptoms are reported correctly that there is more to this story than reported.
i.e. The locks didn't work when you bought the car from somebody rather than they have "just" started not to work and this was omitted for brevity etc .

Stuart