The tire pressure light could be one bad TPMS sensor.... you will have to take it to a dealer or indie shop to have them put it on a STAR machine and tell you which one (if any) is bad....
If you dont care about the the light you can do a DIY fix that disables that light... it is posted here somewhere.....it works good...

CEL could be anything.....do you have a OBD II reader to see if you are getting any error codes??

The security system has it's own computer.....SKREEM module.... How old is your battery??