Pontiac Repair: pontiac g-6 2006, p0128 thermostat, coade

Question
I TOOK MY CAR TO GET IT INSPECTED AND IT FAILED BEACUSE THE CHECK ENGINE WAS ON.  THE MECHANIC SAID THAT THE COOLANT WAS LOW SO WE FILLED UP.  THE LIGHT STILL DIDNT GO OUT AND WE HAD DRIVEN IT FOR 1/2 HOUR LIKE HE SAID TO DO. HE THEN SAID THAT THE COADE THAT WAS FAILING MY INSPECTION WAS OBD CODE. WHAT DO I HAVE TO DO, IM NOT ALL THAT GREAT WITH CARS. PLEASE HELP ME.

Answer
Hi Samantha:

well it depends on what caused the lamp to come on in the first place. if it set a p0128 thermostat/cooliong system code yopu "may" have fixed it. or it could have a bad thermostat causing the lamp to come on. in ofer for the lamp to go out if indded just filling it up fixed it it will need to be driven at least 2 more drive cycles meaning fully cooled off and driven up to operating temp. if after the 3'rd drive cycle the engine computer sees the fault gone the lamp will then turn off. Now if the lamp was on for any other reason your just wasting your time and gas driving it around. take it to a shop that knows what they are doing and have it looked at. good luck :)