Volvo S40 2004-2009, V50 2004-2009, C30 , V70 , XC70 XC90 SID803A**
THIS IS FOR 803A & CEM UNIT WITH MCU TYPE MC9S12DT256 (1K79X , 1M14E , ETC ) TTHIS TYPE OF MCU IS ENCRYPTED WHICH MAKES IT DIFFICULT TO READ AND PERFORM SYNCHRONISATION. THE CEM UNIT CAN BE IDENTIFIED WITH THE PART NUMBER OF 8690722 THERE WILL BE OTHERS. IF YOU ARE UNSURE PLEASE CONTACT ME FIRST!

These modules can lose sync from voltage drops IE. Dead or dying battery...
or sometimes happens when the battery is disconnected.

Some of the common symptoms are:
Car not starting due to loss of communication with the CEM unit (central electronic module)
and a message appearing saying *IMMOBILISER TRY START AGAIN*

POSSIBLE FAULT CODES
C326 Communication control module
C326 Communication control unit, Permanent
if you are also receiving fault code 6c48 this is somtimes can happen in conjuction with the battery going flat.

if it is found that the cyrpto key is missing and the keys are missing from the data dump you will need to send your keys in to be re-added too the cem unit. THERE WILL BE AN EXTRA CHARGE FOR THIS SERVICE