[Daveoff]

Hello, I have a 1999 E430 Sport, and in the last year or so, the trunk has been sluggish to open, and once open, it takes about 15 seconds for the latch to "reset" so it can be closed again. Not a huge deal, but annoying sometimes. I know the Pneumatic pump under the rear seat controls the latch, but all other functions are OK except the trunk. Could it be a clogged or leaking vacuum hose between the PSE and the latch, or a sticky latch that takes a while to reset? I know I could just begin to take it apart and look, but I figured maybe someone has had the same issue and knows what it is.

Thanks,

Dave

 

[Kajtek1]

Sticky trunk latch doesn't sound like problem related to PSE pump.
Take it apart as much as you can, wipe off the dust and spray with graphite lubricant.

 

[mrboca]

Hello, I have a 1999 E430 Sport, and in the last year or so, the trunk has been sluggish to open, and once open, it takes about 15 seconds for the latch to "reset" so it can be closed again. Not a huge deal, but annoying sometimes. I know the Pneumatic pump under the rear seat controls the latch, but all other functions are OK except the trunk. Could it be a clogged or leaking vacuum hose between the PSE and the latch, or a sticky latch that takes a while to reset? I know I could just begin to take it apart and look, but I figured maybe someone has had the same issue and knows what it is.

Thanks,

Dave

With the rear seat removed, press the trunk open button, and check if the PSE is still running after the trunk is opened. Also check the indicator on the remote trunk release button at the center console. The red LED should be lit as soon as the trunk is opened.

 

[Daveoff]

Thanks, I don't think its related to the pump itself, as the other functions work, I was thinking it may be that particular vacuum hose clogged or leaking that may be slowing down the latch. when I open the trunk, I can hear the PSE running for about 10-15 seconds. I hear the latch clunk, the PSE shuts off, and the trunk can be closed. When I open the trunk by pressing the keyhole on the trunk lid (the only way I basically ever do it), I need to hold the button in for about a second or 2 before it will unlatch. I does sound like a sticky mechanism, but I figured maybe someone had this issue before and it may have been a leaky vacuum hose.

 

[mrboca]

More like a leaky actuator at the trunk latch. You need to remove the hose that goes to the RTR (rear trunk release) from the PSE, and apply positive air pressure about 9 to 10 psi, and check if there is any leakage it should hold the pressure at least 1 minute. If that is the case, you need to access the actuator and check for any cracks.

If it is a stuck mechanism, you can check that too while you are there.

 

[Daveoff]

OK, so I removed the trunk latch mechanism, and it has 2 small electrical plugs, and the pneumatic hose from the PSE attached. There is an actuator attached to the pneumatic hose that has a small piston that moves downward when you depress the trunk button to open the trunk. That works, but on my car, the PSE stays running for about 10 seconds, during which time the piston is down, holding the small trunk release lever open. When the PSE finally "gives up" and shuts off, the piston retreats and the trunk can be closed. My guess is that on a properly working mechanism, the piston would move down, unlatch the trunk, and then immediately stop and retract and allow the trunk to be shut again immediately. My guess is that the PSE requires some sort of pressure feedback to shut itself off, and its either not getting it for 10 seconds, or it just gives up after a certain amount of time. The probable reason its not getting it is that there is a leak in either the hose leading to the trunk latch, or the actuator has a leak. it would be good if it was the actuator, as it looks easy to change. Does anyone know if that part is available as a stand alone part, or would you have to purchase a whole (expensive) trunk latch? I did a quick search, and did not come up with a trunk actuator as a part.

Thanks,

Dave

 

[khomer2]

Dave,
PnP are always a good source of inexpensive components. You would just have to remove it yourself.

 

[mrboca]

That is why I asked you to check the red light on the center console after you press the trunk release button. I believe when the trunk is open,a signal is sent to the PSE and the PSE sends a message to the center console to turn the light on. If no signal from the switch, the PSE gives up.

 

[Daveoff]

I did check, and there is a light on the console on the trunk switch when the trunk is open. The console switch and the button on the trunk behave exactly the same. the trunk opens, but the PSE stays on and holds the trunk latch open for about 10 seconds. When it gives up, the piston retreats and the trunk can be closed. the big question is why is the PSE staying on? it has opened the trunk. Does anyone know for sure if its looking for pressure feedback? I did find the actuator as a part and ordered it (wasn't too expensive), I did change it and it made no difference. I can only think it could be the hose, or the connection at the PSE

Thanks

 

[mrboca]

All you need to do is to do is to remove the vacuum / pressure hose from the PSE for the trunk and apply positive pressure of 600 millibars (about 9 psi) and check for pressure drop. If there is a leak in the hose, the pressure will drop. The PSE has a built-in protection against leaks so that the pump motor will not burn out. Regarding the feedback, there is a trunk release signal from the trunk switch to the PSE which will indicate if the trunk is open or closed.

 

[Fotoflame]

I have an issue with the trunk opening and closing that is similar. When I lock the car, all the doors lock and the pump quickly turns off. When unlock the car, all doors unlock immediately, but the pump continues to run for about 10-15 seconds and within that time the fuel door lock takes a while to unlock and the truck won't open within that time. After the pump runs from unlocking, the trunk will eventually open with the pump being on for about 10 seconds afterward. If you try to close the truck while the pump is on, it won't close.

I haven't had a lot of time to figure out the problem, I'll have to read through all these replies to see if they help.

 

[mrboca]

I have an issue with the trunk opening and closing that is similar. When I lock the car, all the doors lock and the pump quickly turns off. When unlock the car, all doors unlock immediately, but the pump continues to run for about 10-15 seconds and within that time the fuel door lock takes a while to unlock and the truck won't open within that time. After the pump runs from unlocking, the trunk will eventually open with the pump being on for about 10 seconds afterward. If you try to close the truck while the pump is on, it won't close.

I haven't had a lot of time to figure out the problem, I'll have to read through all these replies to see if they help.

Start with the fuel tanks filler flap line. It has a separate line connected to port c on the PSE. Remove the hose from the port c and apply positive pressure to see if it holds the pressure.

For the trunk issue, it could be the line that goes to the remote trunk release actuator which also goes to the rear headrest release. Application of positive pressure should open the trunk, and sustain pressure (no leak). Application of negative pressure (vacuum) should drop the rear seat headrests if they are up. It is possible that the one of the headrest actuators is leaking, so when the PSE applies positive pressure to the trunk actuator, some of the air is leaking from one of the headrest actuators or lines.

 

[brooktre]

On my 2002 W210 Sedan, the rear driver side door would not unlock when I activated the remote unlock from the key fob. All other doors / trunk / fuel flap unlocked. The rear driver side would lock remotely with the key fob. This failure to unlock started when the front driveshaft failed and the car was abruptly stopped.

During this time, I noticed that my trunk started to have a delayed opening when activating the switch on the console. Sometimes it would not open on several attempts. I’m not sure if the problems were related, but after I replaced the rear drivers side locking actuator, both problems were fixed.

 

[mrboca]

On my 2002 W210 Sedan, the rear driver side door would not unlock when I activated the remote unlock from the key fob. All other doors / trunk / fuel flap unlocked. The rear driver side would lock remotely with the key fob. This failure to unlock started when the front driveshaft failed and the car was abruptly stopped.

During this time, I noticed that my trunk started to have a delayed opening when activating the switch on the console. Sometimes it would not open on several attempts. I’m not sure if the problems were related, but after I replaced the rear drivers side locking actuator, both problems were fixed.

If the trunk had opened with the remote but not from the console key, it would have been unrelated.