I have a 2002 S 60 non turbo Stick shift. Recently my wife had a dead battery and when I boosted it a light came on saying "SRS airbag. Took it to the dealer and they reset the computer.
The light came on again 2 months later and the dealer said there was an issue with the seat belt. Probably a glitch and reset the computer again.
A third time the light came so I disconnected the battery thinking this may reset the computer but instead there is still the SRS Airbag on and now no power for the Defrost and AC STC button and back window defrost on the panel.
Took to the dealer and they were able to reset the SRS airbag but could not reset my defrost control panel. They said the DIM was not communicating the the CCM Code. There suggestion was to replace the DIM at $1100 and if that did not solve the problem then replace the CCM module at $1740
Why would the Defrost fan and AC stop working from the battery disconnect? Is there a cheaper fix? The car is only now worth maybe $5000

 

some of my electrical systems were not working and my DIM was not working either. I bought the repair service on ebay by BBA ($193). took a week to send it in and get it back. i drove the car the whole time it was out. (feels really weird) some things do not work window,sunroof,seat heaters, mirror,door locks, etc. the climate control system worked manually but no ac just heat and you have to turn the fan off when you exit the car. However after installing it back, everything now works great and just get the codes cleared and your good. The DIM is easy to remove and the fix is fast, well worth not being irritated trying to trouble shoot.

 

rbdc, repair DIM module as pdg914 said.
Than have dealer to try to reload CCM module software.(sometimes it becomes corrupted when you connect the battery). Or go to the junk yard and look for the same CCM module (same model year, engine and etc.) The lower buttons on the CCM do not need to be the same. You can install yours later.

 

Already, the dealer is not sure if it's the DIM module or not. They seem to be eager to make you pay.

If the DIM module doesn't communicate with the CCM, it's nothing to worry about. It's just that the airbag system could not display information if it would be needed.

There might be a loose connection in the center console that prevents the DIM to communicate with the CCM. I would fix that first, before replacing anything and go see a different dealer.