bobinyelm

2002 C320 Wagon

I recently had my car's headliner replaced, and as part of the procedure, the battery was disconnected as a safety precaution by the shop.

Tonight (weeks later) was the first time since this repair that I actually tried using my sunroof, and it's NOT happy.

The tilt-up feature works fine, and the close function works OK (though the auto-close does not, though holding the switch to "Close" is fine w/ me).

What is screwed up, however, is that pressing the switch aft to OPEN the sliding function only makes the glass open about 1". If I then go back one click (auto-open), or release and re-position to Open, it moves back one additional inch. In order to open it fully I have to press "open" and release, then open, and release, over and over until it is fully open.

I reviewed the manual (Page 190 in my C320 Wagon owner's manual) that discusses "Synchronizing the sliding/pop-up roof" (i.e., "The sliding sunroof must be resynchronized if the power supply has been interrupted (battery disconnected or low)..., but that procedure (raise the roof and hold for one second) didn't seem to do it.

The sunroof is not obstructed, or otherwise jammed, and as I mentioned, it DOES slide smoothly closed in one motion if the switch is HELD in the "Close" position.

Any other solutions?

Unfortunately, I dare not disconnect the battery again, because my State Inspection is coming up, and the last time the battery was disconnected, it took well over a MONTH of normal driving for all of the required OBD II "Readiness Monitors" to reset so they would pass my car. I can't afford to have my vehicle taken off-the-road for such a failure-to-pass again.

Thanks,
Bob
(Yes, I misspelled "Berzerk" but I guess one cannot edit the thread title. My bad, and I once won my 2nd Grade Spelling Bee, too. I hope Mrs. Keating, my teacher of 58 years ago, will forgive me.)

SunnyRayToronto

Maybe you should re-read that part of the owners manual. I think its more like to resynch the sunroof,.... close the sunroof,... press and hold the button,... for about 30 seconds,... as I recall,.... certainly quite a bit more than just one second. But then mine is a coupe with pano,.... anyways, try it and report back.

Moviela

Thee SAM measures the current being drawn by the roof motor to determine when it is against the open or closed stop. Loss of voltage causes the SAM to forget the measurement. If there is mechanical binding due to lack of lubrication the motor current can go over the threshold and cause the motor to stop. Don't use any lube other than the Mercedes specified Dupont Krytox. It is stupid expensive, but less than a new roof motor.

Open the roof until it hits the open stop and continue to hold the switch for ten seconds. Then hold the button closed stopped forward, then 10 more seconds.

The automatic functions will now work if the current when moving is less than an amount that would damage the motor.

Resync the door windows the same way.

bobinyelm

Problem Solved!

I discovered the "solution" before reading the SECOND reply (Thanks, both!). The manual didn't mention running it AFT, the FWD 10sec (only popped up), but next time (if there is one), I will try that as well.

1) First, the manual says to raise the pop-up sunroof and hold for 1 second.
Problem was that while I THOUGHT the sunroof was popped-up ALL the way, it wasn't. Like the aft movement, "up" was only giving partial up, so it was not against the stop. I had to press it up in 3 stages until it was FULLY raised. Only THEN, of course, would the system be able to resynchronize when the second condition (switch held) had been met.

2) The manual says to hold the switch for ONE second (I re-checked just to be sure). When I held it approximately 4 seconds (until the dome light went from slightly dimmed to full bright, indicating that the current draw has ceased) after the sunroof was FULLY opened, plus a couple of seconds more "for good measure", the system "Resynchronized" itself and now works normally.

There was, thankfully, no mechanical problem (such as binding).

Thanks for the inputs!

Comment: I liked the "old" controls with wired connections and no computer involvement, but such is life. Why do things now have to be so complicated.
Maybe I'm just getting old (an unfortunate truism), but I LIKED being able to re-set my clock, or being able to use every feature my car offered w/o referencing a 385 page owner's manual!
My first MB, a 1958 "180" back in 1968, was SO simple. MY W123 cars and W107 SL seemed just as straight forward. I'm not sure the "computer age" has made operating our cars more satisfying unless one was brought up on computer games!
Of the 9 MBs I've owned, however, I DO like driving my current ones (the W203 Wagon an a R107 SLK) the most so maybe I should just stop complaining and enjoy them, though I did like the "built-for-a-lifetime" feeling I got in the old ones!
At this point MY lifetime is shorter than back then, so I am sure these will last me just fine, though.

Moviela

Without the computer controls your car would have many more wires and and heavier switches to do all the jobs. Your fuel economy would suffer, and you would not have the neato "tunnel mode" function.

bobinyelm

I'm sure the car would be 50 pounds heavier, but all that fuel economy can go out the window pretty quickly with one visit to a tech that might not have been needed years ago, so it's all a trade-off I guess.

My W123 and W107 cars got great fuel economy (25-30mpg) with mechanical diesel injection and Bosch CIS, as did my 1980's vintage BMW e23, 24, 28, and 32 cars (at 26-28mpg equal to my W203) and with the Jetronic injection, and I could diagnose and repair anything on the cars myself.

Today most of my friends lease cars and give them back before the warranty ends after having spent $4000-$5000 on single repair visits w/o warranties with both MBs and BMWs, and are now too frightened to risk that again.

I have a cousin that tops that w/ her Range Rover ($6000-$10,000 every year in maintenance, near D.C.), so I guess I should just count my blessings with my 2 entry-level Benz! So far so good-no big bills, though the $250 replacement key and the $250 charcoal canister shut-off valve seemed a tad pricey.

SunnyRayToronto

After disconnecting battery,.... I think thereis 5 things that needs to be resynch. Sunroof, window,.... ESP, HVAC system,.... I do not recall the 5th. So I must be getting old,...

bobinyelm

Hmmm.....

I've done the windows and the sunroof, but the HVAC and ESP appear to be working normally, or at least no fault codes or lights.

Are they (and the missing 5th item) mentioned in the owner's manual, or somewhere here?

SunnyRayToronto

You should resynch them anyways,... even if ESP and HVAC "appears" to be working normally. You do NOT want to discover the ESP traction control is not working properly when you need it!

All resynch are mentioned in owner's manual near battery disconnection/connection section. I still can't recall what the 5th one is,.... maybe it's the power seats,... but my coupe doesn't have power seats,...

bobinyelm

I didn't find that section, but I'll look again. The resynchronization procedures I found were right with the power window section, and the sunroof section.

They weren't indexed, but I went through pretty much page-by-page to find them.

I'll have to see if somewhere it addresses everything that needs to be done w/ a battery re-connect.

Thanks-

SunnyRayToronto

Instead of looking for indexes,.... that's soo old school. Get a pdf version of the owner's manual. Glyn already created a sticky at the top of the forum,.... linking to MB-USA site with the various owner's manuals. Much easier to find and search in pdf.

bobinyelm

Old School-yep, that's me alright.

Hey, I still like my Blaupunkt radios with knobs!

Thanks-