2008 Kia Optima Q&A
2008 Kia Optima Question: How to turn off malfunction indicatop lamp.
It should clear if you remove the NEGATIVE cable from the battery for a few seconds however, if tightening the cap corrected the problem, the light should turn off after 3 drive cycles. (A basic drive cycle involves starting the car cold, i.e. after sitting over night, driven normally until reaching operating temperature, then turning the engine off). You said the cap was loose. Did you have a trouble code P0455 or P0456? - Rojo1