water coolant light

my water coolant level is on, but the coolant tank is filled with antifreeze. What could be causing this. The car was recently at the mechanic because it was heating and the electric fan wasn't working. Now the fan works and the tempature of the car while running doesn't even reach the half way point of the tem. gauge. Then just to add more to it the check engine light came on as well as the ETS light. I have changed the spark plugs and boots and air filter and still Check engine is on. Please help. I wish i had a manual.

I had the exact same problem lol now to boot the low fuel light cam on with half a tank of gas in my car and i can smell a slight gas odour all the time, I think I will wait until it just stops running then get it towed to the shop and they can fix it all at once lol. I cannot see anything wrong and it runs fine.....weird I even disconnected battery overnight.

Well i fixed some of the stuff. My temp gauge was acting up and if found out as i was checking the thermostat that it was almost completly gone just the pin was hanging so i replaced the thermostat and fixed the problem. My check engine light was going on because one of the ignition coils was failing i took it to autozone to get a engine check and they came up with p0300 and they said it could be the plugs or the ignition coils. I had just replaced the plugs so the guy said they can check the coils there at autozone so i took them out there and sure enough one of the two coils was bad and that fixed my problem. The car was practically runnign on two cylinders. Disconnected negative battery for 30minutes and no more check engine light.