TysonEtc

Hello everyone hopefully someone can help. My 1998 S420 has all the doors locked I can only open the trunk manually. The vacuum pump seems to have failed. The latch on the trunk is stuck inside. I replaced the car battery and my key fob works. (lights flash as if door locking mechanism works) When I try to turn the key in the driver door nothing happens. Windows will not go down. I only have master key. Fuses are not blown, I also tried to remove and replace in hope of pump resetting. Nothing happened, Hopefully someone can help Thank you

Alex-587

I have never experienced this issue before, but if you are able to fully open the trunk, I would suggest locating the sun roof release.
It is a flap, usually on the left side of the trunk. (Google "W140 emergency sunroof release" to get a guide on your exact model of vehicle.)
I have attached a picture from the manual which shows the tool. It should have come with the car, but if you don't have it anymore, you will need a 16mm tube spanner,
needs to be at least 170-200mm. You can then spin the gear which will allow you to open the sunroof.
Beware that you need to do this manually and not with a power tool as it may strip the wormgear.
You will then be able to jump through the sunroof and manually open the doors from the inside.
(This is assuming that your sunroof is able to open and not broken)

Sunroof release


You can also locate the vacuum pump to try and test it. (Note: You have to remove the fuses about 30sec - 1min to reset the system)
There are other threads on where to find/remove it. Once you have the pump located, there should be markings on it such as: ZV, RH, FKS, etc
The ZV which I assume stands for "Zentralverriegelung" in german, is used for the locking system. (Not soft-close!)
Depending on the model of the pump there will be 5-6 vacuum lines going to each of the door mechanisms or one line from the pump going to a distributor and then the doors.
If you lock/unlock the vehicle the pump should make an audible sound and pressure applied to the ZV lines.
If the motor has failed it is possible to replace it without buying a new pump assembly.

Hope this helps!

DEALER.

Hi!

Have checked in trunk right side fuses
You need check fuse number:3
Pump for central locks is located in saloon under see video.

shopcarpro

I was in same situation and was managed to pop the L.Rr lock with a slim Jim.

You will have to study the mechanism from another car which I did since, I own few W140s.

If I remember correct , I had to push a linkage horizontally rearward to get the lock to pop up.

Need to take the window scraper rubber out frm door.

Good luck.