lpg

Audi A4 1.8 litre (2005). Left key in the ignition overnight and the car wouldn't start. Tried bump starting it but that didn't work. Tried jump starting it, the lights turned on and the engine was about the turn over, but it didn't and the car won't start at all. Is there some sort of a reboot that needs to happen in order for the battery to now power the engine and start the car?

jagtoes

You may have to go back to Audi to have them reset the charging system. Before you do that remove the battery from the car and have it tested and charged or replaced. If replaced make sure it is fully charged. Also with the battery removed touch the positive battery to the negative battery cable to reset the system. Install the battery and hook it up. Do the plus (positive) terminal first and then the negative. See if it starts then. If it doesn't then you need to go to a dealer.