Electric Vehicle Forums - No hybrid mode

I am new here, but I have owned my 2009 Silverado hybrid for about 3 years. Had to put a new engine it at 158,000 miles, now at 165,000 miles. My main problem with it now is when I pull up to a stop with the gear selector in Drive, the gas engine shuts off like normal, but when I give it gas, it will no move. As soon as I put the gear selector in Manual, the gas engine starts back up, and it goes like normal. It throes the check engine light on, I don't have the exact code handy. It is time for inspection, with the light on, it will fail. I can reset the light, but as soon as they pull it in, and it screws up, it will throw the light on again. I don't even know where to start with this one. I have regretted buying this truck from day one!! Any one have an idea where to start checking?