Upper electronic module (UEM)
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2007 Volvo V70, 2006 Volvo V70, 2005 Volvo V70, 2004 Volvo V70, and 2003 Volvo V70. However, it is still accessible from the selected car via links, so may be relevant.
Upper electronic module (UEM) receives the signals from the remote control and checks that the remote control belongs to the vehicle. For the upper electronic module (UEM) to be able to perform the check it must be programmed with codes for the remote controls belonging to the vehicle. If the key being used is approved then a request is sent for unlocking or locking to the rear electronic module (REM).
Upper electronic module (UEM) communicates with the rear electronic module (REM) via the low-speed side of the CAN network.