Hello all i'm new to this. my service engine light on my 2001 X5 3.0 just came on, thought i'd check it i bought a scanner months ago hooked it up and did what it said and got codes p0171 , p0174. unhooked scanner and went to start my truck and got nothing not even a click but when i turned key my headlights came on then went out, no i don't have auto headlights i have to turn knob for them to come on. my battery is 3 months old so it is new everything works. it's like it's in shutdown mode. i read where if you disconnect battery for an hour it will reset computer, not sure if that will do anything. need help got to get to work to pay the bills am i overlooking something. Thanks