2001 ML320 - Locking System Malfunction

I own a 2001 ML320 that has been trouble free . . . until now. I presently own two other Mercedes that are and have been excellent vehicles over a period of 19 years.
The 4 year warranty of the ML320 is about to expire and the dealership's service technicians do not have a clue as to what is causing the malfunction(s) of the remote locking system. The dealership has made 4 unsuccessful attempts at fixing the problem(s).
The malfunction is intermittent and can be described as follows:
1) Inability to lock the doors after the car is parked, the lights are off, seat belts off and the ignition key has been removed.
2) The interior chime (ignition and or seat belts warning signal) sounds off after opening the driver's door, the car is parked, the lights are off, seat belts off and the ignition key has been removed. The vehicle cannot be locked with the remotes.
3) After driving the car back home from the dealership, the doors were locked with the remote. Moments later we tried to unlock the doors and the remotes (2) would not unlock the doors. The dealership advisor told us over the phone to unlock the doors using the key (not the remote). When this was done, the door unlocked but the theft alarm was set off by itself and turned silent only when it timed out.
The dealer has replaced the driver door jam switch, the ignition switch, driver's door latch assembly and the ignition key tumbler.
My next move is to setup a meeting with the Dealership's Service Director, the Service Advisor and a Mercedes Benz Representative.
If anybody has any good suggestions as to the cause and solution of the problems, please let me know. Please post your replies to these newsgroups and to my e-mail address.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You are on the right track getting the regional service director involved... so bear with them.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hernando Correa wrote:

I have had the same problem and it's a defective part in the ignition switch. There is a microswitch inside the steering column that detects when the key is inserted. When there is a key in the ignition, it disable the remote locking functions.
The best solution is to replace the clockspring, actuating lever, and the detection switch. My guess is that your dealer replaced some of these parts but not all. The most interesting part of this problem is that your key can be removed and the detection switch is released, so you won't hear the reminder chime, but when you return to the vehicle later, the switch has "somehow" re-engaged! To me, this seems to point to a defective switch (which I don't believe is part of the ignition switch assembly).
--

- RODNEY


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Rodney T. Grill wrote:

I am printing your reply and will give a copy to the advisor at the dealership. I have an appointment (the 6th time) on Monday, May 16, to have the ML serviced again. The foreman said that he ordered all the parts that need to be replaced in the steering column...
Interesting enough, my wife and I went out for dinner tonight and locked the ML knowing that the remote was OK. When we came back to the SUV, I could not unlock the doors! I used the key instead of the remote and the theft alarm went off. Exactly what you described when you said that the switch has "somehow" re-engaged!
Hernando
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.