W140-PSE pump
 

The power doors and trunk handle failed a few days ago. Today, I removed the pump and reviewed a broken nipple on the P + Pressure connection, it is also the first one I pulled. I don't think I caused the broken nipple, prior to pulling the connector, I hear a single click whenever I push to open/close doors. I also hear air noise when the engine is running.

Will this broken nipple cause the failure?

Jack

Update
 

I used some vacuum to connect the broken nipple, but it does not work.

The motor clicks when I turn on/off the doors.

What's next, does anyone know how to repair the pump.

Jack

P+ is pressure for the lumbar, P- is vacuum for HVAC. I dont know of anyone who has successfully repaired a pump for any extended period of time. I would pull the plug on the pump wait for a few moments and power up. The pump has a safety if it runs too long it diasbles it, if you cant hear the motor run ...well. The pump provides constant pressure for the lumbars, provides vaccum for the engine/AC/ when accelerating or at "rest". ZV is switched vacuum / pressure for lock and unlock, pressure to unlock, vacuum to lock. SFG is for the lid grip. You are probably hearing the relay(s), but not the motor.

I also have problems with this pump.
I see that the P+ pressure connection is divided into 3 pipes.

Look at this picture (blurry cellphone image taken in my 1997 S320)

http://www.pvv.org/~syljua/merc/PSE.jpg

I think I have read somewhere that;

The yellow ones are for ZV and boot.
The single white is vacuum from engine.
The black are vacuum back to HVAC.
The double white are for read headrest?
The disconnected pipe (not shown) are the grey one beeing divided into 3 grey ones on the left for the lumbar.

Why 3 for lumbar? (there are only 2 seats?) Am I loosing something else
here?

How does the rotaty dial on the seat regulate the pressure on
the lumbar support?

My pump does not give pressure on this connection at all. Even
after disconnecting it for a while. But all the other functionallity works
like ZV, HVAC and rear head rests down.

br,
syljua

The vacuum lines are grouped together as follows:
Clear = Vacuum supply from engine (1) to fit to a one way connector
Black = trunk handle eject/retract (1) to fit to a one way connector
Red = Rear parking aide antennae (2) to fit to the two way connector
Yellow = Central locking (6) to fit to the six way connector
Grey = Front seat lumbar (3) to fit to the six way connector with 3 vacuum plugs
White/blue = Rear headrests (2) to fit to the two way connector

Yes, but my 1997/1998 car has PTS (no parking antenna) and the new AC.
Does not this unit give vacuum to the AC when engine is not running?

The number of yellow ones does not make sense.

And why are the lumbar given vacuum, not pressure?

br,
syljua

Syljua, It is my understanding, in later years, MB introduced a "universal" PSE pump for our model of car. Your car's options or features will dictate the number of adapters/hoses you will connect to your PSE pump. I have an older model W140, and as a result, my car uses the connections for the rear parking aids. This option would be capped off for your installation.

As Peter mentioned, P+ is pressure for the lumbar - not vacuum.

pse
 

Russel is correct in color of tubes. The xtra pressure tube could possibly be used for the optional side bolsters (different lumbar switch). The picture looks like the universal replacement pump, but why all the crimps & splices. They had two pumps with and without headrests, and then the rods were eliminated. The final is a universal and requires a hose kit.
There also was a change ( service note 93/94) where the handle was moved from the locking pump to the closing pump. this required shorting out a switch, redo on the hoses and changing the lock. The 95 version also handled the lid release, with another solenoid in the line...
The pump basicly has a motor that runs forward and backward, the output is routed thru solenoids to whatever source needs it, the valves are controlled by microswitches, or electrical diaphrams that start or turn off the pump. The whole system is also controlled by safeties, and timers.

Thank you for the replies. As rebuild pump is not available, I found a new pump in Houston for $425.

Jack

I purchased a rebuilt from George Murphy at

Performance Analysis Company
1245 Oak Ridge Turnpike
Oak Ridge, TN 737830

Home 865-482-9175

George is MB National Tech Director MB Club of America.

Seems like the price is $295 + $75 core.

Russell

I email George, his price is the same. He only rebuild older pump, and does not rebuild new model pumps.

Jack

The crimps and splices are introduced by the man
installing alarm in my car. He had trouble with the trunklid, and
sensing which way the pump goes, so he obviously had
to access the inner workings of the pump...

One warning, I managed to get the electrical connector divided into
socket and ca. 20 connectors. It was a nightmare to get it together again.
Never release the fasteing grid of the small connectors!

If I can diagnose and fix the lumbar connection from the pump on,
how will I be able to tell the pump to try to give pressure once
again? Fuse? Which one in the trunk? Are the pump trying to always
feed pressure to the lumbar, or is it regulated by electric signal to the
pump?

br,
syljua, W140 S320 1997/8

There is a reservior in the trunk for the lumbar support that maintains pressure for the lumbar support backrest. The pressure reservior is on the passenger side of the trunk, below the lining, next to the trunk hindge.

Make sure you have a 3 grey lines connected to the P+ or Pu on the PSE control module.

Wow! never knew that Russel, I had the panel with the lumbar switch off and was surprised to get air flow, the pump must be on the same circuit as the seats (work with the door open, and no key, or door closed need ign. on). Thanks

Great!

Will look at the tank in the trunk.

How can I re-enable the pump giving lumbar pressure?
Do I have to clear some error-codes or must I visit MB when
I have fixed the leakages?

br,
syljua
W140 1998 S320