RUNTIME VERIFICATION OF SHUTOFF CONTROL LINE INTEGRITY IN A HYBRID VEHICLE SYSTEM

A control system and diagnostic method for a hybrid vehicle having a hybrid powertrain each utilize a controller comprising (i) a hybrid control processor (HCP) and (ii) a motor control processor (MCP), a monitoring circuit that is distinct from the controller and is configured to monitor operation of the HCP and the MCP, and a gate drive circuit that is distinct from the controller and the monitoring circuit and is configured to enable/disable torque output by the hybrid powertrain based on first, second, and third independent shutoff signals. A diagnostic method performs a shutoff line integrity verification routine by performing six steps corresponding to different combinations of shutoff signals in a predetermined test sequence. These shutoff signals are provided to three independent shutoff lines, which are connected between (i) the gate drive circuit and (ii) the HCP, the MCP, and the monitoring circuit, respectively.