Ok. Just wanted to double check before moving forward. You can retrieve the Diagnostic Trouble Codes or DTC's for that system by grounding pin #8 in the data link connector (that pin should be fore a white wire) which should be under or on the lower portion of the dash on the drivers side and may have a rectangular plastic cover over it.
While grounding this terminal your check light will flash each code 3 times in pulses that you can count. Code 12 should flash first and if there are any DTC's they will follow. So code 12 would be 1 flash-pause-2 flashes and again 2 more times, then the DTC's.
The DTC's will give an idea of what part of the system a problem might exist.
This procedure can be done by you or your local mechanic if you have one that you use. This is a good place to start.
If you need any other info please feel free to ask even after you accept my answer by returning to this page. You can bookmark page if you'd like.