Q: ECU is disconnected and I can't program a new key. I lost the original key

Hi there. For your vehicle the ECU is showing a battery disconnect to the ECU for either a loose battery cable or a loose connection. Check the battery terminals and make sure that they are tight and clean from any corrosion. If the cables are tight and clean, then check the harness to the computer and make sure that the ground wires are tight to the chassis. If everything seems good, then remove the ground cable to the battery and let the computer reset for about 2 minutes and then put it back on tight. Then reprogram the key to the vehicle. Once you have reprogrammed the key, take the key fob (if it is on the key) and put the key in the driver door. Lock and unlock the door 3 times to allow the computer to finish the adjustment programming. If you have a key fob and a key separate, then put the key in the driver door and at the same time that you unlock the door with the key, touch the unlock pad on the key fob. Then do this to the unlock cycle. Do this a total of 3 times for lock and unlock and the key fob will be programmed correctly. If you need further assistance with your key fob reprogramming, then seek out a professional, such as one from Your Mechanic, to help you.