Can't remove ML55 ignition key

Is the key turning through the full range of movement in the lock?

Thanks for your quick reply mhpautos, though I appreciate your question, I had hoped I'd covered the obvious things. No the key can not be turned back to ''O'' otherwise I would be able to remove it.

As you will know, there are mechanisms, be it cable or electrical switching that stop the key being removed until the shift is put into P.

In my case the 2004 ML55 dose not seem to have a mechanical method to stop key removal when in D/N, ie cable, so it has to be a micro switch that isn't being opened or closed when the shift is moved to P.

Please can you advise is the mechanism that stops the key being returned to O until the shift is put into Park, mechanical or as I think electrical & how do I get to it to adjust or replace it.

Thanks, cheers, merc1122

I have just attempted to log onto Mitchell 1 database to look for info on your problem, they are currently off line due to unknown problems, i will try again soon and post any relevant info.

Reading the available info it appears that the lock is at fault see pic for there description of problem, there are 2 special tools required to remove the lock cylinder.

Thanks for that mhpautos, but can't see the pics, here's one I just took of the gate, though as you say it may be the lock cylinder. The problem started after my wife couldn't get the shift into drive, & beet hell out of the stick, before realising the brake pedal needed to be depressed before trying to move the stick. It was fine before that, hence thinking it was a problem with the stick not communicating with the ignition switch.

How do I view your pics?

Thanks for your help, merc1122.

Well it would actually haep if i push that button that says load pics... sorry

Also i am looking further into the electronics, i will let you know what i find, you can ask your local dealer if they concur with the faulty key theory, worth ticking that box one way or the other.

Thanks again, needless to say the first thing I did was to lubricate the lock barrel, the problem happen two days ago. The car is drivable of course, every thing works OK, just can't remove the key. I disconnected the battery in the hope that it would reset things but all that achieved was to make me reset the clock & find out how to get rid of the ESP warning light, which turns out to be, drive the car & the steering resets the warning light.

My guess still is that a micro switch that allows the key to return to O isn't being activated by the stick when in P. The problem is how do I get to it without taking the car to bits.

As you will have seen from the pic of the gate, there are no screws or even plastic release clips to remove to find out whats under there & yes the center console may have to be removed.

I will look forward to what you may find out about the electronics, cheers.

I spoke to friend who is a Benz tech, he says that it sounds like a faulty lock & key, but it really should be scanned with a Benz factory scanner to make sure.

Thanks mhpautos, as I can't afford to risk disabling the ML55 just now, I haven't got any further with the problem. I did speak to my local M/Benz garage, who said they could put it on their computer next week but also said it would only show all the things that could be causing the problem not necessarily the actual problem.

As you know, I have been lead to believe the ignition switch is connected to the shift, to stop key removal while in drive, if your M/Benz tech friend says its a ignition switch barrel/key problem & he should know, perhaps there is no connection to the stick, & it is a mechanical ignition switch problem. Could you check this out with your friend please, is there any connection between the shift & the I/switch. If not the cause of action is more straight forward.

Thanks again, cheers, merk1122.

There is usually a button that must be pushed on the shifter in order to release it from Park so it can be shifted into Reverse and Drive. It does seem to me as if there is a switch, whether electrical or mechanical, that is not being activated when the shifter is put into Park. Behind the switch there should be a pin that is released when the shifter is put into Park, allowing the key to be removed. You need to get to the back side of the key switch to determine why that isn't happening.