Gas electric with convection oven ( 48600)

Old message but maybe you are still living with the problem.
There are safety switches that must close with the oven door before  the cleaning cycle will initiate and one or more of these may have failed. Sometimes these are actuated by metal tabs on the oven door that fit into slots on the mating surface. If yours is so constructed, use a popsicle stick or similar non-conductive probe and poke it into each slot listening carefully for a quiet 'click' or a change in resistance to your insertion. If one of these sounds or feels different than the other, one of them is probably bad although finding an action doesn't guarantee that the switch is electrically functioning. Unfortunately, if your oven is constructed as described, the switches are only accessible by removing the side panels from the range.     
The door lock feature is a must since the self-clean temperature must reach 900+ degrees to enable the catalytic action to occur.