Have Mercedes Questions? Ask a Mechanic for Answers ASAP
Hello,There is a fusebox under right rear load compartment, which has a fuse for central locking. Please check all fuses there first of all.
The car is currently at an auto electrician. They have opened the box under the rear pacel box and exposed the fuses. I assume those have already been checked. They have also dismantled the the boot lock mechanism, a lot of the wiring in the trunk is exposed. After two days they still have not identified the fault. I did not say what had already been tried because I do not know exactly. All I have done is, replace the battery with a new one, fully charged it, reset the windows and the ESP. The car starts with the plastic key and the doors can be locked with the emergency key. I have replaced all the batteries in the keys and the "Keyless Go". I understand that I have to have the "Keyless Go" reprogrammed by an MB dealer. Unfortunately there are very few, if any, of these cars in Nelson, where I am located. What I am hoping to do is perhaps get some information that will help the electricians to pin down the problem.
I forgot to say, when the key buttons are pressed, the alarm sets and the lights flash. Pressing unlock turns of the alarm and the lights flash again.
Ok, it seems that PSE module (pneumatic system for actuating central locks, controlling alarm and door statuses) has failed. It is located at the left side of the trunk, below hydraulic pump for convertible roof
please have the electricians disconnect it- this might reset it.
Also let them open PSE module to see if any water got on it's internal electrical plates
A very common problem is that electric motor for vacuum/pressure pump fails- so it is good to check it's resistance and how it runs when car is locked/unlocked
It is also inside the PSE module. If it fails- door position signals will not be clear for convertible roof and it will not work
That is interesting. If I try to open the roof there is a pulsing noise from the area of the pump. It continues for a while then stops. It also stops if I restart the car but if I touch the roof switch again the pulsing starts. Also I think I noticed it starts if I touch the door handle but I am not certain.
There are two pump modules there- one is PSE (pneumatic) and one is hydraulic for the roof. Hydraulic is right on top of PSE. It is quite hard to detect which one starts making noise.
Thanks, XXXXX XXXXX do anything until Monday. I will pass on your information. I will click the accept button. How can I contact you again if I need to?
But if hydraulic one starts running, but roof does not open- i suspect a problem with roof position switches. It is best to have this issue checked out with Star Diagnosis computer- some independent Mercedes shops have it besides the dealers. This tool is needed to communicate with PSE, Convertible top and all the rest of controllers
Save a link to this internet page, and even after accepting, you will be able to post a reply. I will get back to you as soon as possible
We can communicate on this matter for as long as necessary.
Thank you very much Stan.
Sorry, you do not have my name.