Ignition Trouble

Need some help to determine what correct part to change out. I have a cook top. When I turn any knob to start cooking the only spark I have is the front 2 burner. The back 2 burner will not spark even if I turn the back knobs. I can use a lighter to start the flame. I have remove the back burner and switch it to the front. I have try to use the front electrical connector then tape it off and use the back connector to see if the burner igniter was bad. It was not, both time using the back or front connector to start, it started and the burner had flame. I left the front burner in the back and turn the back burner knob and still only the front had spark? My S # 15580854AC & M # JGD8130ADB. Any help would be great!