I don't know but mine is doing the same think. Letg me know if you find out.
The fuse box and battery are under the back seat on a 2003 Pontiac Bonneville.
Under back seat.
It is under the back seat.
I HAD A 1990 BONNEVILLE I HAD THE SAME PROBLEM WITH.IT TURNED OUT TO BE THE CRANK SENSOR.ITS BEHIND THE HARMONIC BALANCER. HOPE THIS HELPS
Disconnect positive side of battery for at least 5 minutes, worked for my 2002 Pontiac Bonneville. Dealer wanted $50.00 can you say rip-off!
In many of the larger GM cars like the Bonneville, the battery is located under the back seat cushion. Need to take out the seat cushion and you will see it mounted in the middle...
Go to Radio Shack they wii replace it
remove battery cable for 1 min
COULD BE THE CRANK POSITION SENSOR
A group 78 is original equipment, though a group 75 will work in a pinch.
TRY DISCONNECT'IN BATTERY FOR A FEW MINUTES IF NOT AN HOUR OR SO.
The Battery is located under the rear seat. Pull up slightly on the bottom of the back seat and it will come up and out and there is the battery and fuses and all the electrical wiring.