I drove to post office to get my mail. When got back in the car, and tried to crank it up, the key turned but nothing happened. Now, the car won't start. "Service Engine Soon" and light with "oil pan" sign stays on. But before i turned off the engine, there were no noises, no overheating. I had the oil changed a month ago, and don't drive but 3 to 5 miles a day. Checked the oil, still good, checked battery, fuses etc. Any help will be greatly appreciated. I am on disability, so hoping not anything major...