The three bolts you mention secure the PCM to the firewall. The two screws are below the connectors, one below the gray, and one below the black. The heads face forward toward the battery. You should be able to feel them if you can't see them. If you still cannot locate them, remove the connectors and you can't miss them. When removing or inserting the connectors, remember to disconnect the battery ground. Also, there are locking tabs on the top and bottom of the connectors which must be squeezed together to unlock them.