BD Diesel s Auto PressureLoc optimizes your exhaust brake s retarding power automatically. When the torque converter isn t locked up during exhaust brake application, you only get a fraction of its potential. Auto PressureLoc commands the torque converter to lock up and stay locked in third and fourth gears, enhancing engine braking and keeping transmission oil temperatures low due to zero clutch slippage. At low speeds, the lock-up clutch and exhaust brake disengage to avoid stalling and prevent damage to the transmission and converter. Additionally, Auto PressureLoc boosts fluid pressures to prevent slippage and ensure positive clutch contact, maximizing efficiency and safety.