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It will suck (a slight) vacuum but won't supply positive pressure. The pump whirs in the background, so I'm suspecting something is wrong with the pump assembly or there is a huge leak somewhere that I'm not detecting.
I will dig into the car tomorrow, but maybe someone can shed immediate light on this. These cars have a lot of inherent flaws incompatible with their complexity...
It will suck (a slight) vacuum but won't supply positive pressure. The pump whirs in the background, so I'm suspecting something is wrong with the pump assembly or there is a huge leak somewhere that I'm not detecting.
I will dig into the car tomorrow, but maybe someone can shed immediate light on this. These cars have a lot of inherent flaws incompatible with their complexity...
Hello,
My doors will lock with both the remote and the button on the dash. It will not unlock on both the key and dash. So I know it is not my Key fob. Have you found the solution? I checked my the hoses and there is no leak. The soft close doors work on all 4 doors. Any help would be appreciated. Also, I was fooling around with the module, and was wondering if the white thing is in the correct position between the 2 metal pieces. Picture attached.
Thank you
Henry
2003 S500 LWB RWD
Last edited by HankWank; Feb 8, 2025 at 04:09 PM.
Reason: spelling
My doors will lock with both the remote and the button on the dash. It will not unlock on both the key and dash. So I know it is not my Key fob. Have you found the solution? I checked my the hoses and there is no leak. The soft close doors work on all 4 doors. Any help would be appreciated. Also, I was fooling around with the module, and was wondering if the white thing is in the correct position between the 2 metal pieces. Picture attached.
Thank you
Henry
2003 S500 LWB RWD
For locking and soft close the system supplies positive pressure, for unlocking negative pressure. It seems your negative pressure supply is broken.
Your fuel door is probably stuck locked, to unlock it you have to remove the trunk liner, reach in with your hand, and physically pull the metal tube thing back.
For locking and soft close the system supplies positive pressure, for unlocking negative pressure. It seems your negative pressure supply is broken.
Your fuel door is probably stuck locked, to unlock it you have to remove the trunk liner, reach in with your hand, and physically pull the metal tube thing back.
Thank you for your quick response. yes the gas door was locked, and I figured out how to unlock it. I want to know what your solution was for your car. When you say my negative pressure supply is broken, are you referring to within that black box or outside of it?
Thank you for your quick response. yes the gas door was locked, and I figured out how to unlock it. I want to know what your solution was for your car. When you say my negative pressure supply is broken, are you referring to within that black box or outside of it?
Thank you for your quick response. yes the gas door was locked, and I figured out how to unlock it. I want to know what your solution was for your car. When you say my negative pressure supply is broken, are you referring to within that black box or outside of it?
thank you.
henry
I haven't dug into my car yet. I'm still fixing the passenger door
My doors will lock with both the remote and the button on the dash. It will not unlock on both the key and dash. So I know it is not my Key fob. Have you found the solution? I checked my the hoses and there is no leak. The soft close doors work on all 4 doors. Any help would be appreciated. Also, I was fooling around with the module, and was wondering if the white thing is in the correct position between the 2 metal pieces. Picture attached.
Thank you
Henry
2003 S500 LWB RWD
Looking at that picture again, I think the contacts got misplaced. They should both be on top so when the white guy gets pushed up it has them make contact and shuts the pump off.
I think some of the pneumatic lines might be slightly clogged... When I removed them I heard a gentle hiss coming from the line, which you wouldn't expect from a clean line.
I'm suspecting the graphite veins inside the motor pump assembly might be broken. There are replacements available in the $50-$100 range.
I'm increasingly thinking this is what happened, but it's also possible the solenoids are bad. Here is an instructional on how to replace the impeller veins:
you have a large leak somewhere (mine is trunk leak, i bricked my pse pump and doesnt even turn on anymore)
my scanner tells me which circuit is leaking based on an error code
did you do that yet
there is an inline filter too
you said your pump turns on if i remember right. so you know thats normal right. and it runs until it finds there is a leak. and or pops the fuse. this is basic PSE information
Last edited by e350forme; Feb 12, 2025 at 01:46 PM.
you have a large leak somewhere (mine is trunk leak, i bricked my pse pump and doesnt even turn on anymore)
my scanner tells me which circuit is leaking based on an error code
did you do that yet
there is an inline filter too
you said your pump turns on if i remember right. so you know thats normal right. and it runs until it finds there is a leak. and or pops the fuse. this is basic PSE information
I have it on the bench. It runs, but it feels like it's not supplying enough pressure? 30psi is ideal/brand new for pressure.
I have parts for it on the way, but I'll explore for leaks first, and if I find none, I'll check the impeller.
The PSE controller is programmed to sense the change in positive or negative pressure when it is doing an operation, and is also programmed with the expected time that the operation should take. If an operation takes longer than the expected time for several cycles, the controller simply stops trying to do that operation. The controller can be reset by briefly unplugging the yellow 20-Amp fuse located behind the floor lamp behind the right rear passenger's heels.
I've gone through and tested the basics: the filter does not seem clogged. I'm hesitant to test the solenoids in the circuit by ***** nilly supplying voltage. I measured 32Ω across all of them in vivo.
The black carbon dust stuff pictured is likely graphite, potentially having clogged something internal to the PSE ports, or the impeller is simply worn out and not supplying appropriate pressure. Unfortunately I'm not seeing any easy way to test this that I can tell. I hate guessing here, I'm surprised there isn't more/better info available.
I think I found the issue and fixed it: inside the pump unit, mounted to the end of the motor, the inlet port got clogged with graphite:
If you enlarge the pictures you can see there is a mesh filter on the inlet that was clogged up. I didn't go crazy cleaning it, only compressed air at ~40 psi.
For the disassembly and reassembly.
The torx screws need to be tightened to a specific tolerance tolerance to maximize pump output w/o squeezing the impeller to death.
Per the above video: hook the output up to a gauge, run the pump off a battery, tightening the bolts until output is maximized (in the video they achieved ~3 bar, 43 psi).
If you don't achieve that, loosen and realign the pump casing. (just watch the video thoroughly lol)
Last edited by Fried Chicken; Feb 13, 2025 at 12:16 PM.
I want to find someone who can help me; I need to buy a W220 PSE pump because mine burned out. Is this a common issue in this car? Given its age, it's time to start replacing some parts. If anyone can provide information on where to buy one, it would be greatly appreciated!
Most of the second-hand ones I'm seeing are over 300 euros. Does anyone know a place where I can get it cheaper? Any link would be appreciated. I'm in Spain. Thanks!
No help whatsoever with finding a pump in Europe, but some comments/suggestions...
The PSE Pump consists of two main assemblies - a PUMP unit and a CONTROL/VALVE/SOLENOID unit. They bolt together.
In general, any PUMP unit will work on any car.
The CONTROL/VALVE/SOLENOID unit must be programmed to match the options installed on your particular car. If you buy the complete PSE unit, it might, or might not, work correctly on your car.
Sometimes you can find one of the pump units for sale, but most offers are for the complete PSE unit. You can try installing one and see if it operates the options that you have, and if not, you can swap your old CONTROL/VALVE/SOLENOID unit onto your "new" pumpunit.
WARNING, WARNING, WARNING!!
No matter how you choose to solve your PSE problem, it is CRITICAL that you know exactly which airline goes on which connection! Do not remove any airline until you have multiple photos and sketches showing the proper connections.
I have a quite common problem with lumbars/multi contour seat on W220 2003. No airpressure at the MKL-port.
Everything else on PSE works well, door assist, locks, trunk etc.
The pump is overhauled, no excess running time. Good pressure. The pneumatic block cleaned.
When the lumbars or massage is activated, the relay clicks, but nothing happens. Same thing, when trying to activate with sds.
The control box under the seat is changed, no help.
No fault codes. Can-bus o.k
The pse-pump remains silent.
If there was a huge leak, the pump suppose to kick in for a few seconds at least before entering protective mode.
I suspect the pump electronics.
Fuse ok, all semiconductors measured, all coils and pistons checked. New O-rings on solenoids. The coding is "lumbars active"
People use to change the pump unit, and a few are repairing these. But I would like to know why the electronics wont let the pump start. Anybody struggled with the problem?
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w220 PSE pump
