Underlying cause of 10 error codes
 

My 2004 Volvo S60 (70,000 miles) has had intermittent electrical issues its entire life. I've taken it to one Volvo dealer who reset the codes and did a software update, and another dealer who did a full diagnostic and recommended replacing the DIM (drivers information module) for about $1800. I did not have confidence in his diagnosis and declined.

The error codes are below. I don't see why replacing the DIM would fix all error codes. Maybe doing software updates of all systems could do something for me. If you need me to post the car's symptoms and error messages, I can do that, but I'd rather find an underlying cause of the problems than replace one system after the other only to find that the problem persists.

The error codes were:
AUM-E003 Configuration fault, Faulty configuration
BCM-0100 Communication between control units, Communicational problems with ECM
BCM-E003 Configuration fault, Faulty configuration
CEM-1A62 Communication with ECM control module, Signal missing
CEM-1D08 Control module, Internal fault
DDM-0025 Mirror motor, Signal missing
DIM-E003 Configuration fault, Faulty Configuration
PSM-E003 Configuration fault, Faulty configuration
SRS-00D5 SRS lamp, Configuration fault
UEM-0080 Rain sensor, Signal missing

This is very difficult to point down without having VIDA, you need to check your battery and see if voltages are good out of the alternator. You may have a CEM issue here. You can try a full reset by disconnecting the negative and positive off battery and touching them together for over 15 minutes. Reconnect after.

Problems recurred, dealer did a hard reboot, ran some diagnostic, upgraded the software on the DIM and CEM. They suggested replacing the DIM, but once again, that was only a suggestion. If that doesn't work, they recommended another part. Seems like a black hole that I'm not gonna throw my money down... not unless I'm sure it'll fix the problem. I wanna replace the CEM (covered under emission warranty), but they'll only do that if there are some emission-related error codes. The error codes that came up in this check up were as follows:

CCM-E003 Configuration fault, Faulty configuration
DDM-0025 Mirror motor, Signal missing
PSM-E003 Configuration fault, Faulty configuration
CEM-1A23 X-supply relay circuit, Signal missing
CEM-1A25 Relay Ext X2-Supply Signal too low
CEM-1D07 Control module, Internal fault
CEM-1D08 Control module, Internal fault
CEM-3F03 Shift lock signal, Signal too low
CEM-6C48 Transponder type, Faulty signal
CEM-1A21 Relay Ext X-Power supply, Signal too high
CEM-1A24 Replay Ext X2-Supply Signal too low
CEM-1D0C Control module, Internal fault
DIM-E003 Configuration fault, Faulty configuration
AUM-E003 Configuration fault, Faulty configuration
BCM-E003 Configuration fault, Faulty configuration
BCM-0150 Stop (brake) lamp switch, Signal outside its permitted range
PDM-E003 Configuration fault, Faulty configuration
PDM-E003 Configuration fault, Faulty configuration
PDM-0030 Rear view mirror potentiometer, Faulty signal
PDM-0032 Rear view mirror potentiometer, Faulty signal