there is no error condition set 712 described the circumstances under which the state will transition from delay state 706 back to off state 702 after a 10 second delay the first subset of conditions corresponds to no error occurring and the inhibit switch 701 being moved affirmatively to the down position a second subset of conditions corresponds to the inhibit switch not being up and the parked regeneration switch being up a third subset occurs with an engine controller message that it is not inhibited by the inhibit switch and the inhibit switch is not up delay state 706 allows up to 10 seconds to satisfy the conditions to move to on state 704 a transition from ten second delay state 706 to the inhibit light illuminated state 704 occurs as soon as the transition conditions 714 are met transition condition 714 are that there is no error the inhibit switch is not down and either that the parked regeneration switch is up or both the inhibit switch and parked regeneration switches are up and that engine controller acknowledge that regeneration is inhibited and finally that the ignition not be off a transition from the delay state 706 or the on state 704 to an error state 708 follows breakdown in can communication or an invalid switch position a second transition from the on state 704 is possible back to the off state 702 the condition set 710 describes these circumstances which include 1 engine off or 2 there is no error and either the inhibit switch is down or there is a message that the engine controller is not inhibited by the inhibit switch or the inhibit switch.