Sunroof motor refurb

Ever since I bought my 996.1 I've not been able to slide the sunroof, so today I thought I would investigate and see what would cause this. The sunroof has always tilted but has never slid back. I read a lot of the threads and it came down to one of two common issues; the switch or motor. I had an inkling that it was the motor because the switch has always been fine for the tilt. I took the motor out and decided to give it a clean and check all the plastic gears. I found there was a lot of dirt on the commutator and brushes. I used a fibre brush to clean the assembly. While it was apart I also checked the gears and applied dabs of grease where it looked a bit dry and made sure there wasn't any play. Reassembled and end the result is the motor functions so much better and now has enough power to slide the roof!! Next on my list will be to service the sunroof runner because it's not the smoothest when sliding. Has anyone tried to service the sunroof runner before? I hope this helps anyone with similar problems, it only took an hour and worth a try before buying replacement components.

Nice job. So satisfying when you can fix these things without spending anything!

This is really helpful. Thanks I have a dodgey motor that give up the ghost half way so i must try this.

very interesting post! I was considering doing the same as my roof has a tendency to stop and return halfway through closing. :thumbs:

AnthonyC - you are a legend. Just did this. Sunroof motor working great. It just decided to lose the memory function and when I did the reset procedure, the one touch started working again but it had completely forgotten how to tilt... I walked away so I didn't overheat the motor. Just FYI - I took out my sunroof frame completely 3 years ago as like yours it was sticking half way through closing. I cleaned the entire rack etc. I used a battery drill at the time to open and close it and the drill loaded up more during the closing procedure; I.e. it is the mechanism and not the motor that makes it slower to close and puts more load on the motor. Your tip had achieved more for me. So I really advise against taking it out and Lubling it etc. the lube will just attract dirt and you might not make any difference. If it is working now, leave it alone!!! Another issue I have is that my sunroof liner - the upholstered panel - keeps getting stuck during closing and pulls off. I have tried several times to get it to clip on properly. Is there a knack to this that I am not aware of? Has anyone else had this problem? Any suggestions?

Thanks to Antony C for writing this up. One observation that may help anybody who undertakes this: because the brushes are spring-loaded and don't have a lead-in chamfer, I found it impossible to insert the motor windings/commutator assembly back into the steel housing without first removing the pressed steel cap of the housing. This is done by carefully bending the four steel tangs on the housing out of the way to permit the cap to slide off; then the assembly with the brushes can come out the end. After cleaning everything up, stick the motor into the housing, and install the brush assembly onto the commutator while holding the spring-loaded brushes out of the way. Then put a dab of grease in the bushing on the cap, reinstall it and bend the tangs back so everything's held tightly together again.

Thank you both, good tips! Working motor, now how to test the switch?! Kind Regards Edward

This is a timely bump of this thread as I have just replaced my sunroof motor/electronic PCB with a used 997 version and have the same issue as the removed 996. I have previously removed the full sunroof frame assembly from the car and checked it on a bench only to find nothing wrong. So subsequent to nearly 5 years of occasional reading on this topic as my sunroof has never worked per the book, I have determine the following – - when owners on forums say they have replaced the motor and everything works perfectly, they have replaced the motor assembly which included the PCB. - There seems to be two common problems 1) the armature gets dirty as above and the motor is less effective and it can trip the torque switch then closing, so it doesn't close fully. This is mostly solved by cleaning the armature/brushes per the above. 2) the sunroof forgets the one touch function after a few minutes of the ignition being off or when the car goes to sleep. I'll get to this in a minute. - There are 2 reset procedures in the manual. One reset procedure starts at the tilt position. The other starts at the full open position. It seems you need to do both starting with the tilt first. This teaches the PCB the torque load on the motor at the full open, full tilt and closed position etc. If the reset doesn't seem to kick in after holding the tilt button for 10 seconds, you need to close from tilt, open to tilt, press the close button for a second, the sunroof will judder forward a tiny bit, then try the reset again. Eventually you will get it to work from tilt – I have had this conundrum but got it all to work eventually. - The problem I seem to have (which matches the other posts on various 911 forums) is that after I reset, the sunroof works perfectly. If I cycle the ignition it still works perfectly. If I lock the car, then open it again immediately and try it, the one touch still works perfectly. If I let the car go to sleep (5-10 minutes) and then get in an try it, the one touch doesn't work. However in this case when it doesn't work, if I tilt and close the sunroof, the one touch will work again. I'm not an electronic engineer by any stretch of the imagination, but what I have determined from googling electronic circuits is that there is some form of capacitor on the PBC that holds a tiny signal voltage that powers the one touch memory. This capacitor is possibly leaking and hence when left for a period of time (car goes to sleep) it drains completely. Therefore it cant trigger the memory until it is recharged. So when I cycle it open and closed, the dodgy capacitor gets charged again and hence the one touch works as the memory is now triggered. I could of course be talking out my ar$e, but I am currently tying to find an electronics engineer that could test the PCB that I have from my 996 motor assembly that I have on my desk. I've texted my cousin for starters as he is somewhat involved in electronic engineering. Failing that, there is a chap that was an intern in my company a couple of years back who builds electronic circuits for fun that I will be sending a whatsapp to. If anyone has any thoughts, please share. Hopefully this could be a relatively easy electronic component fix that will save people having to replace the entire assembly which currently costs about £600... This is a link related to memory circuits https://digilent.com/reference/learn/fundamentals/circuits/memory-circuits/start This is a link to someone testing a sunroof PCB https://www.youtube.com/watch?v=3BGPBCe1d1g

This is the PCB

Very interesting thank you. Having taken my motor apart yesterday my next question was whether the PCB's ever fail etc and how to test them etc! I am not sure if you can buy these, I have not seen much mentioned on them, only the motor, switch or the track.

is the 997 PCB/Motor upgraded over 996 or the same btw? Best Edward

Just found this, its seems the PCB and motor is almost the same in the Infiniti (Nissan) G35, both made by Siemens:- https://rennlist.com/forums/996-for...repair-for-cheap-with-infiniti-g35-parts.html 996 sunroof one-touch repair for cheap, with Infiniti G35 parts The sunroof one-touch functionality on my 2004 996 C2 Coupe had stopped working, which seems like a common issue. I tried the reset procedure and that would work until the car was turned off and then it wouldn't work again. I didn't spray the circuit board with electrical cleaner (also from here) but that's probably worth trying. Instead, I saw that Feparra had asked 'I was doing a quick research on the Porsche 996 sunroof motor and came across the motor used on an infinity G35 which looks exactly the same as the Porsche one. Both are Siemens with part numbers 770.60003. Of course a fraction of the cost on eBay! Has anyone here tried to retrofit one of these motors on their Porsche?" I bought an Infiniti G35 motor from eBay: the 2003-2006 Infiniti G35 sunroof motor has the same Siemens part number, just search for '770.60003". I paid $32.55 delivered. I took off the sunroof switch panel using these instructions and took out the motor. Unfortunately, I saw that the parts were very similar but not exactly the same. Specifically, the gray cylindrical part was longer on the Porsche unit than on the Infiniti unit. I didn't want to replace a stronger motor with a weaker motor and have it fail later (maybe they're totally interchangeable, eg if Siemens figured out how to make the part smaller but just as strong, but I didn't want to chance it). However, I did change out the circuit board, within the black plastic housing. It's held on by one Torx screw, and then a couple of tabs that need to be loosened. After reinstalling everything, it works! I have one-touch again! However, the button behavior is a little different, my guess is that the G35 has only two buttons while the 996 has three. The CLOSE (front) button now does nothing. When the sunroof is closed, hold TILT to tilt open. When the sunroof is tilted, hold CLOSE to close. When the sunroof is closed, press OPEN to open. One-touch! When the sunroof is open, press CLOSE to close. One-touch! Previously, when the one-touch functionality was working, the sunroof would open about 85% and then if I pressed OPEN again it would open 100%. Now, it goes straight to 100% open. So, the functionality is a little different than before, but, I'm totally fine with that because one-touch open/close works again! I thought I'd post this because I've found other writeups so helpful, and I wanted to share something I'd learned. I much prefer spending $32 on an G35 sunroof motor, than $400+ on the Porsche unit. BTW I should have said "swap the black plastic boxes" not swap the circuit boards. No need to take the circuit board out of the housing! Just swap the black unit completely. [/i]

I found the Infinity thread too last night. There are similar motors used in many cars such as Citroen, Mercedes, BMW, but its the PCB that differs. The 996.2 sunroof assembly is used in the 997.1 and possibly 997.2. the 996 motor assemble P/N changed to the 997 P/N and they are ultimately the same. They both suffer from short term memory loss. I phoned a PCB company this afternoon and they said the cost of a repair would be the manhours spent trouble shooting rather than the potential £2 component cost, but they told me to send photos of the PCB and he'd let me know what he thought. My thinking is that if you could identify the rogue component, while it might cost £200 to get the first pcb troubleshooted, on the second they could test the rogue component straight away and therefore the cost would be greatly reduced. Far cheaper than buying a new assembly. There must be at least one electronic engineer on here that could test my now spare PCB if I cant find anyone in Ireland. Alternatively I send it to MyMateVince on YouTube and wait for a year until he gets around to it!

Thanks for this re circuit board etc. I don't know how to test my switch to see if that is faulty, any ideas as that must be an easy thing to test? I have tested the motor (without PCB) using a battery and it is ok.

i just got a call back from the PCB repair guy. He said the square chip with 23 on it (i think he called it a prom https://www.electronics-tutorial.ne...c-Devices/Programmable-Read-only-Memory-PROM/ ) has firmware on it that controls everything and that the firmware will be corrupt. This aligns with the issue in the video link up above in this thread . He said that while it is possible to replace these you would have to flash the new one with good software. to obtain this software you would need to have a second fully working motor/pcb unit that you could take the prom off, download the firmware and then transfer it to the new PROM and then reinstall both working proms on to the the two motors. His thoughts is that it is simpler to buy a new motor assembly. My thoughts are there must be someone that can do this at an enthusiast level even just to test the theory...