cd changer not working after cabin air filter & battery replaced

I would take back to where you got it serviced. If it worked before then they are responsible. They could have disconnected something when changing the cabin filter or shorted something out changing the battery.

Is your cd changer an in-dash one, or is it in the glovebox or the trunk somewhere? When the battery was disconnected and the vehicle wasn't hooked up to a memory saver, it quite likely could have caused a problem with the CD changer like it tripped the changer's security system and it's looking for a code to unlock it again, or the head unit doesn't realize that you have a changer if it's located elsewhere..... Most cabin filters, especially in Japanese cars, are behind the glovebox and inside a compartment. You probably have two clips, one on each side, in the glove compartment's storage... With those removed along with the release strut/brake setup unhooked.....if your glovebox opens slowly instead of all at once dropping open, then you've got a release strut or something in there that will need to be disconnected as well. Then you can remove the contents of the glovebox and set the thing aside and look for the cabin filter..... I'm tellling you how it's accessed so you can look for something obvious inside of there that may have been disconnected while they were in there and forgot to reconnect it. Hope this helps.

HI did you solve your problem ??? I'm facing the same issue Please help if possible my email is soofi_85 at hotmail.com If you found a solution please send it to me thanks

on one site someone said if a code is entered 3 or more times without reboot success, it can affect the cd player ????????