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Sunroof not closing properly

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1. With the ignition switched on, press the "lift" button and move the lifting/sliding roof drive to the "raised" limit position.

2. Press "lift" button again and keep depressed. After around 10 seconds, a complete cycle takes place from the "raised" limit position to the positions "lower - open - close".

3. Teaching of the characteristics has been completed after this process.


The "raise" button must not be released during the entire process. In the event of a restart, the lifting/sliding roof must always be moved to the raised limit position first.

4. If the lifting/sliding roof drive should move back in Item 1, then the closing force limitation function has responded (lifting/sliding force drive was taught). The "open" button must be re-taught in this case.


1. Press the "open" button until the sliding roof stops. Then release the button. Press again until the lifting/sliding roof drive stops again. Then release the button.

2. Press "open" button again and keep depressed. The entire process takes place after approx. 10 seconds: "close - lift - lower - open - close"

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  • 8 years later...
  • 2 months later...

Same issue on my 2004 and I have followed steps to a "T" with car on as well as with just ignition on and it goes through all the learning steps but then as soon as turn it off back to same issue.

Manually holding buttons sunroof works fine and if you tilt it firs then the close it the one touch will work fine as well.

Used to one touch until recently I just don't get it. Replaced switch and had Indy look at and he's perplexed as well.

Edited by MiamiC70
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  • 1 year later...

Sorry to resurrect an old thread. Just wanted to get advise because I recently changed the sunroof motor on my 99 c2.

So I got a used power window motor off ebay and installed it today. Took out the overhead center panel to gain access to the motor. Took out the old noisy motor and installed the new one. Very simple to take out and reinstall: 2 t30 torx screws and the electric wire connector.

However, and this is now the NEW problem/issue - when you press the open button, the roof goes all the way to the back (not like before that there is around 10% left of the sunroof not going in the ceiling). When you push to close it, the sunroof will only close 80%. It wouldn't go further even if you push the close button continuously. To close it fully you have to push the TILT/raise center button BUT will sort of tilt the sunroof about 5%. The sunroof will not tilt fully like before.

I tried the sunroof button initialization procedure where you press the open button continously for 5 seconds. But still nothing happens.

Should I...

Disconnect the battery to reset everything?

Is this the right way to reset all electronics on the P?

Is there any other secret to this sunroof issue?

I reinstalled the old one until I find a solution. Even the old one now is not aligned like it used to be. When you fully close it from tilt position it does not go 100% up but only around 95% meaning water can easily pass thru.

HELP please! :-(

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  • 10 months later...

Well worked for me until I turned off the ignition and started it the next day.  I went through the procedure multiple different times, to no avail.  Seems others are having this issue?  Any fixes?


"This worked great for me!  I thought it was the switch, this fixed the one touch closing issue!"

Edited by Chicagospeed996
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  • 4 weeks later...

I have the same issue on my 1999 C2.  I can retrain it, and then it works fine (one touch, etc) for about 5 minutes, and then "forgets".   Other posts claim replacing the motor fixes the problem, but it's an expensive fix for something that still sorta works.  


Some engineering thoughts:

My sunroof moves fine, maybe a little slowly, but not to the point of it sensing overcurrent and reversing the motor.   Since it "forgets", I thought there might be a simple power supply problem to the microprocessor inside.   The motor is a Siemens part, and the electronics inside look straightforward: a Motorola microcontroller, a Siemens chip that might be used to sense a magnetic encoder on the motor shaft, relay, and a few jellybean SMT parts for the switch inputs, etc.  I don't really see any parts that would impact the power supply; there is one electrolytic 47uF cap but it looked fine and tested at ~47uF with my DMM.  If I had had the time I would have swapped that out with a new one.   There's a few small diodes and one larger diode, they tested ok in-circuit too.   I didn't see any external memory (EEPROM, etc) so I assume the training parameters are just kept in SRAM in the microcontroller while it's powered.  Or perhaps the microcontroller has some internal non-volatile memory for the parameters, and that no longer works?   


I was short on time so I just tried reflowing the solder around some of the components, but didn't want to go too crazy; a half working sunroof is better than none.    I cleaned the connector contacts and reinstalled everything and it works just as before:   relearns and operates fine, but forgets in about 5 minutes.   :-(    Perhaps the current draw from the motor drops the voltage down low enough to trigger the controller's power-on reset?  But that still doesn't explain why it works fine for the first 5 minutes...


Have any other electronics-savvy RennTechers looked into this?


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  • 2 years later...

Apologies in advance for resurrecting an ancient thread....the left rear corner of my sunroof headliner is bunching-up on something inside the roof slot.  It will open all the way, but then has great difficulty closing again because of this catching gooey liner.  I'd like to remove the sunroof liner and see if this is still a problem without it (maybe replace with a salvage alcantara).  The instructions I've read are that the roof needs to be tilted up and liner needs to be carefully and manually pulled forward to unclip from the rear retention clips...this makes perfect sense...but then it says I need to keep pulling a further 1-2 inches which doesn't seem possible in tilt mode (as far as I can tell).  Can anyone offer more thorough instructions on how to remove this panel without breaking any of the 18 year old plastic clips?  Hoping this is easy!  

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