PES / VACUUM LOCKING problem W210
 

Does anyone have a diagram of the hoses from the PES?

I am at a loss as to how the trunk locking works. (I suspect it's the prob). I have searched forums for hours and am ready to go at it w/the mity-vac.

Symptoms: Pushing dashboard lock/unlock or trunk release buttons gets the pump to run (about 10? seconds) but no red light in the button; sounds slightly different lock vs unlock, but no lock or unlock; fuel, trunk or doors.

I did sync using MB DOC's instructions for a '96. ALARM Seems to work normally; no lock/unlock, though.

The (Rear) headrest release works fine. Does this mean the PES is OK?

Turning key in driver door or trunk gets normal red / green mirror flashes and pump runs. windows shut.

Two button pushes don't unlock trunk as normal.

Disconnected hoses from PES one at a time and cannot feel any vac/press from the nipples.

TIA for any help

Does the gas flap door lock & un-lock properly? IF yes, the vacuum element on the trunk itself is the most likely issue.

will look when i get home. vaguely, in the recesses of memory, i seem to
remember i have something. it may not be a diagram/schematic. it may
be a simple photo of the rear but i doubt that would be helpful since you
would simply view the back of yours.

Thanks for the quick reply. No, I should've been clearer (hence the edit), the central locking does not work at all. When I did the key sync the alarm seems normal but no locking or unlocking. Fuel flap included.

Is there a weak point where the tubing flexes or would you bet on the servo/diaphragm trunk actuator itself?

Since nothing seems to work (I am doubting, but not sure, that the headrest locks are vacuum) I would guess it's the pump itself. The electric motor that you hear running would seem to mean that electrically it is OK, but the actually pump is bad.
If you want to verify on the headrests, like look for vacuum lines under the rear shelf in the trunk, that would help.
Gilly