Automatic Deactivation Of The Parking Brakes

Fig 1: Identifying CAN Network

Courtesy of VOLVO CARS CORPORATION

This means that the parking brake is automatically released when the driver drives off. A condition for this is that the parking brake was activated when the car was stationary. The following information about the vehicle is required for the park brake module (PBM) (4/115) to release the parking brake at the right moment:

• current gear (only automatic transmission), from transmission control module (TCM) (4/28) via the CAN network
• the engine torque, from Engine Control Module (ECM) (4/46) via the Controller Area Network (CAN)
• the vehicle angle, from the vehicle angle sensor in the Park Brake Module (PBM)
• the clutch pedal position (only manual transmission), from the engine control module (ECM) and central electronic module (CEM) (4/56) via the CAN network
• the gas pedal's position from the Engine Control Module (ECM) via the Controller Area Network (CAN)
• driver buckled up, (only automatic transmission), from Supplemental restraint system module (SRS) (4/9) via CAN-net.

Park Brake Module (PBM) uses the information above to calculate when the engine torque is sufficient for the vehicle to be stationary when the parking brake is released.