SL/R129: 1999 Mercedes SL 500 Roll Bar Issue
For what it's worth. I had a similar problem. My roll bar was stuck in the up position. It deployed after running over a tire which caused my car to lift off the ground momentarily.
No matter what I did, the roll bar wouldn't go down nor would the top open. I had the usual blinking red light on the top switch. I finally disconnected the battery and the hardtop controller for about ten minutes.
After reconnecting the controller then the battery, I tapped the top switch maybe five times, then it lowered and the top open.
what you are describing is a peculiar case. You may have done the right things, but I have to put out some serious cautions for others.
Did you follow the reset procedure for a deployed roll bar first, as described in your owner's manual? (Refresher: a deployed roll bar must be reset by pushing the roll bar up position for a number of seconds first, then the roll bar down position on the roll bar button).
If that reset procedure doesn't help, and not before that, erasing the volatile memory in the controller can help. That is indeed done by first disconnecting the negative battery terminal. Remember to re-connect the negative terminal last. Ideally, the negative terminal just gets left disconnected over night.
Capacitors inside the control module keep the volatile memory in place up to several hours. You can speed up the reset by shorting positive and negative battery terminal (after the negative terminal has been disconnected!).
The roll bar being stuck in the down position is not usually a controller issue, and I'm posting this response mostly to warn people about taking the proper steps for controller resets in general. The controller is very expensive, and can easily get ruined by static electricity or excessive arcing at the battery, or by voltage spikes from disconnecting the battery with the engine running.
Klaus
klaus@tophydraulicsinc.com
as far as I understand, you are going to tackle the roll bar switch next. As mentioned in a previous response in this thread, you need to take out the radio and the climate control in order to remove the wood grain console cover. Radio and climate control removal requires a special removal tool, and removal is easy with that tool. Here is one I just noticed on eBay for $1: http://www.ebay.com/itm/Mercedes-Rad...f6f21f&vxp=mtr
Hope this helps,
Klaus
What about the solenoid sensor connector ?
Check it as well, but you'll have to remove rear passenger carpet to Check it.
Here a tutorial i wrote :
http://mercedes-benz.forumactif.com/...cm-sur-sl-r129
http://mercedes-benz.forumactif.com/...ide-sur-arceau
Here how to remove the center console :
http://mercedes-benz.forumactif.com/...tre-les-sieges
http://mercedes-benz.forumactif.com/...e-sur-sl-r-129
Sorry it's written French, but pics are better than words.
Regards,
Frenchy.
Last edited by TheFrenchy; Apr 30, 2012 at 12:30 AM.
BTW, I was already Registered but haven't been there in awhile so the site would not accept my Password. Pain in the asssssssssssssssssss.
Thanks for the info. I'm leaning towards having my friend at Mercedes, The guy that ran the Star Diag. last week, seems to have done it before.
Did you receive my check OK?
Chop
your check has arrived - thanks. As far as I'm concerned, that part doesn't really belong into this thread, as the thread is supposed to help others in the future who are researching technical issues. I would suggest that we both edit reference to that part out of our posts, or delete these two posts.
Filling the gaps for other readers: Chop had the codes read on his car, and came up with no codes for top or roll bar. That makes the switch a very likely candidate. The check that Chop is referencing, is for a used roll bar switch that we had in inventory and shipped to him. Our parts business is currently practically on hold, because we are very busy with rebuilding hydraulic cylinders.
Klaus
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