Brake fade and brake capacity based powertrain operation

A powertrain of a vehicle comprising:

• an engine;
• an automatic transmission coupled with the engine;
• and
• a controller configured to maintain a speed of the vehicle about a setpoint, and in response to a predicted brake capacity falling below a threshold based on predicted brake fade, reduce the setpoint and downshift the transmission to increase a negative torque.

A method of controlling a powertrain of a vehicle comprising:

• in response to a predicted capacity of vehicle brakes decreasing below a predetermined level,
• reducing, by a controller, a vehicle speed setpoint,
• applying friction brakes of the vehicle to reduce the vehicle speed to the setpoint, and
• downshifting a transmission, wherein the predicted capacity is based on a temperature associated with a friction material of the vehicle brakes and a predicted brake fade threshold derived from a speed, mass, and current angle of inclination of the vehicle.