Why do I lose sunroof, ect after battery disconnect?

carboncow · Post by **carboncow** » 08 Nov 2011, 17:52

Did the alternator last night and wife informed me garage door opener, courtesy lights and sunroof didn't work today. Forgot this happened last time I disconnected the battery.

I do have a Vida Dice and the CEM/UEM error didn't show up until I pulled the fuse on the sunroof module. The reason I did this is last time leaving the fuse out reset this issue, this time it will not. I now get the CEM/UEM not communicating with module and am able to reset this and it comes back. WTF is going on now? Is there a for sure trick/steps to resetting this module as I know I did it on two different occasions but do not recall the exact steps of where the ignition was, how many times I walked around the car counterclockwise, ect...

EDIT: Note that I tried the lock/unlock with key in door three times with no luck too. I've read articles about bad security modules but this is not a random failure...the UEM has gone offline three times...and each time when the battery was disconnected!

EDIT #2: FIxed. After repeated Vida resets as well as door lock/unlock x3 nothing got the system to work...then I took the battery offline for 2 minutes and reconnected and all is well. All I can say (again) is WTF! : )

Post by **jimmy57** » 08 Nov 2011, 21:53

Normally the batt disconnect sets the car in "Transport Mode". This greatly reduces battery drain in shipment or storage. Locking and unlocking resets to normal. If a module goes offline for some reason then they can be aggravating to reset. Batt reset usually handles it. Volvo procedure is to go to SOFTWARE tab and then click ADVANCED on the right side. The popup window will have SEND PROG button and a SEND RESET button. Click SEND PROG and then wait 30 seconds and click SEND RESET. When in PROG status the car is dead. No gauges, no nothing. all modules are hibernated. SEND RESET brings them back online. Sometimes this does not work and the batt reset is the Plan B.
DO NOT DISCONNECT BATTERY WHEN IN PROG MODE!!
ASSURE A CAPABLE POWER SUPPLY IS ON CAR WHEN DOING ANYTHING WITH PROG STATUS!!! Over or under voltage can have the same ill effects. Volvo uses an RV 120V AC to 13.4 V DC regulated power supply to assure nothing goes wrong when downloads and other lengthy fault tracing is done.

I'm not sure where lock/unlock 3 or 5 times comes from that I have seen posted here and there. The only place that ever showed as a Volvo repair step is to program remotes on older cars.

carboncow · Post by **carboncow** » 09 Nov 2011, 07:38

Jimmy,

I see through another write up the siren sub-module has a battery in it (prone to leaking too!) and am wondering how many modules or sub-modules have batteries too. I'm wondering if the car battery is offline do these OLD batteries go dead like an old laptop...thus not able to restart until a good juice/jolt to get them going?

I don't believe with my China Vida/Dice I can do software downloads...but I'll review the Advanced/Send Reset.

I do believe the lock/unlock 3 times didn't work for me on any attempts...it was the constant fuse/battery on/off that jolted the system back into behaving!

Post by **jimmy57** » 09 Nov 2011, 10:31

Siren module usually only takes out the sunroof as the siren and sunroof use a network together that goes into UEM.
The reset out of transport mode requires remote lock and unlock. You didn't mention it but did the remotes also not work when the battery was reconnected before you got the reset done successfuly?

carboncow · Post by **carboncow** » 09 Nov 2011, 10:37

The key remote was out too and didn't note until I was trying the 3x lock/unlock theory.

Post by **jimmy57** » 09 Nov 2011, 13:42

UEM is the remote receiver so when it is down you can't initialize network the normal way.

Post by **JRL** » 09 Nov 2011, 13:58

carboncow wrote:The key remote was out too and didn't note until I was trying the 3x lock/unlock theory.

Did you do this (lock-unlock) with the remote?
NO, that does not work
You need the actual key in the door then lock/unlock the car three times,try it, it may work.

Jimmy57
I don't know how or why it works but I have reset several sunroof this way!

Post by **jimmy57** » 09 Nov 2011, 15:28

Volvo may have provided that as a means to do the reset without a remote. They never printed that as a service procedure.
There are several of these secret tricks for various car makes that are not in their service information system.

beetlebob · Post by **beetlebob** » 18 Nov 2011, 06:10

I do not know why this works but I have done this several times. Roll down window,close door and lock it so that the alarm is set. Does not matter if alarm is bad. Wait 2 minutes and open door through open window which will set off alarm(if works). Reset alarm and see if sunroof works. I have had GREAT sucess with this way.

Post by **fazool** » 18 Nov 2011, 10:24

Read this:

https://www.matthewsvolvosite.com/forums ... =9&t=43691