Abstract: A distributed on-board diagnostic (OBD) architecture for a control system of a vehicle includes a plurality of control modules that are in communication with one another and a designated master OBD control module that is one of the plurality of control modules. The master OBD control module performs functions that a remainder of the plurality of control modules are incapable of performing including at least one of arbitrating a malfunction indicator lamp (MIL) state, arbitrating and storing OBD freeze frame data and determining OBD status flags of the remainder of the plurality of control modules.

Abstract: A powertrain braking system for a vehicle includes an powerplant that can be regulated to provide a desired powerplant torque and a transmission that transfers the desired powerplant torque at one of a plurality of gear ratios to provide a desired axle torque. A control module calculates an axle torque command based on a powertrain braking request and determines a shift command based on the powertrain braking request. The control module controls the powerplant based on the axle torque command and the transmission based on the shift command to achieve a desired vehicle deceleration rate that corresponds with the powertrain braking request.

Abstract: An idle speed compensation system for a vehicle includes an idle speed control system that varies airflow to an engine at idle and a transmission driven by the engine. A controller communicates with the idle speed control system, the engine, and the transmission. The controller generates an idle speed compensation signal based on a transmission load.