Engine wouldn't turn off & now won't start
 

A couple of days ago I returned home and pushed the (engine start/stop) and nothing happened. So I pulled the ignition fuse under the hood and the engine shut off and to turn the lights off I pulled the negative battery turminal. Replaced the fuse and the battery turminal and now the car doesn't crank or start. When I press the brake the green light on the start button illuminates button nothing happens... HELP PLEASE

Well you didn't tell us the model and year of your car, but I'm going to say you had a charging system problem that resulted in a weak battery that maybe blew one of the bus fuses. Not 100% sure, but I think if your year is around an '07 or '08, you probably lost your alternator and maybe damaged your battery. Strange things happen to the electronics when the car is running and the voltage starts dropping off. However, this is the first time I've read where the car wouldn't turn off.

2009 is 250 awd
 

[Q.M.UOTE=j0020285]Well you didn't tell us the model and year of your car, but I'm going to say you had a charging system problem that resulted in a weak battery that maybe blew one of the bus fuses. Not 100% sure, but I think if your year is around an '07 or '08, you probably lost your alternator and maybe damaged your battery. Strange things happen to the electronics when the car is running and the voltage starts dropping off. However, this is the first time I've read where the car wouldn't turn off.[/QUOTE]I reset the ecu and while allowing the battery to sit disconnected I pulled the (start/stop engine) to see if there was anything abnormal with wiring and/or connection. To my surprise when I disconnected the switch there was an copper pin stuck in the female connector that apparently broke loose from the start/stop buttons connection. I could have easily purchased a new start button but combining my impatient habits and the desire to repair before replace I opened the connector and soldered the pin to its proper wire, applied heat shrink where needed and reconnected the switch. To ensure this wouldn't happen again I applied a 2 part epoxy to the connection ensuring they will not disconnect or vibrate loose. I then reinstalled the (start/stop button) obviously after I tested the repair. To my excitement the engine roared to life.

I gotta say, that is the first time I ever heard of that one. Glad you figured it out.

I say you got lucky by debugging the root cause timely, good for you.