Exhaust Brake Function - If Equipped
The exhaust brake feature can be used to provide additional braking when the vehicle is decelerating with a heavy load, and/or down a steep grade. A switch provides an input to the body control module (BCM). The BCM sends an exhaust brake request to the ECM via the control area network (CAN). The engine control module (ECM) processes the request and controls turbocharger operation based on various sensor inputs. The ECM commands the turbocharger vane position closed on deceleration which creates excess back pressure in the induction system that helps to slow the engine speed. Any malfunction of the turbocharger or related engine controls hardware will set a powertrain DTC. If the exhaust brake feature does not function properly and there are no powertrain DTCs, the exhaust brake switch and related circuit should be diagnosed.