First thing you should do is check for codes in diagnostic mode.
To enter diagnostic mode:
1. Turn ignition "ON."
2. Depress the "OFF" and "WARMER" buttons on the Climate Control Center (CCC) simultaneously and hold until the segment check appears on the Instrument Panel Cluster (IPC).
To get out of the diagnostic mode anytime during the test, depress the "AUTO" or "DEFOG" button, or turn the ignition switch "OFF." Trouble codes are not erased if this is done prior to selecting "CODES CLEARED."
Here is where you can find out what the codes mean:
http://myweb.accessus.net/~090/dtcobd1.html