Reboot

Post by **fazool** » 24 Oct 2011, 08:55

My 2001 S60 has an issue that my dealer described as a "common problem". Fortunately there is a simple workaround, too.

The symptom is that occassionally, the sunroof buttons will stop working. The home-link garage door opener willl stop working and the manual reading lights will not respond.

Usually the first symptom is when I press the garage door opener (on the visor) and nothing happens. Then, I will try the dome lights and they do nothing.

What has happened here is the Upper Electronic Module has lost its communication link to the Central Electronic Module. basically the two computers have lost their connection.

The solution is rather easy: Simply turn off the vehicle, wait about 5 minutes, then restart and the computers will re-establish their communication. This works every time.

Sometimes this problem doesn't happen for months, other times it will happen 3 days in a row. I would average once every 50-100 times the car is driven. The UEM always works when I start the car but loses its connection sometime during the drive.

The dealer described the issue as more of a design problem and not likely a poor electrical connection. He also wasn't sure about any software fixes available. He said any repair would be (prohibitively) expensive.

The only danger if you have this issue on your car (which happened to me once) is if your sunroof is open and it starts raining: The sunroof controls won't work and you have to turn off the car, wait about 5 minutes and restart the car. And if you are hurrying and start the car too soon and the UEM and CEM don't re-connect, you have to turn it offf and wait again.

My 2007 S60 does not exhibit this problem, so it may be limited to older models.

If you have this type of problem, the best solution is to simply pretend it's running on Windows and "reboot":)

billr99 · Post by **billr99** » 26 Oct 2011, 09:57

Have you had your car completely cleared of DTCs via a VIDA/DiCE? My '02 had what I describe as a variety of "funky" issues like this that would come and go. When I hooked my car up to my DiCE clone, I found I had DTCs from almost when the car was built. That is, it had never been cleared and a number of them were associated with the modules that had these intermittent problems. I just did a wholesale clear to see what would come back. Now after about a month or so, I have not had any of the DTCs return and the reliability of my windows, sunroof, memory seat/mirror settings, etc. have been what they should be. Not saying that is the fix in your case, but it might be worth a try.

Good luck,

Bill

106 Miles 2 Chicago · Post by **106 Miles 2 Chicago** » 09 Jul 2016, 10:48

My 2001 V70 had the same issue, with the home link and sunroof. This occurred, following a check engine lite on which I disconnected the battery to correct the light and then it rendered both home link and the sunroof inoperative.
I did not wait long enough for the reboot per this posted method which failed the reboot. Uff da!
However I tried another technique that was posted which cycled the door locks three times, and everything worked, home link, sunroof and no check engine lite on afterwards.

Post by **vtl** » 09 Jul 2016, 19:41

Do you have a dead alarm siren?

Post by **MadeInJapan** » 10 Jul 2016, 01:15

2 posts up...cycling the door locks means from outside of the car, lock and unlock the car 3 times with the key (not the fob)...this is an old trick that dates back to the 850 days (maybe earlier)...why not give it a try- can't hurt!! The VIDA/DICE clearing of all previously stored codes is intriguing - I had never heard that the car stores codes all the way back to the beginning of its existence.