ABS Description and Operation: Notes
WARNING: This page is about a different car, the 2015 Cadillac SRX. However, it is still accessible from the selected car via links, so may be relevant.
This vehicle is equipped with a Continental Teves Mk25E brake system. The electronic brake control module and the brake pressure modulator are serviced separately. The brake pressure modulator uses a four circuit configuration to control hydraulic pressure to each wheel independently.
Depending on options, the following vehicle performance enhancement systems are provided.
- ABS
- Auto Dry Brakes
- Traction control
- Stability control
- Intelligent brake assist
- Dynamic rear proportioning
- Hill start assist
- Hydraulic brake assist
- Trailer stability assist
- Optimized hydraulic braking system
The following components are involved in the operation of the above systems:
- Electronic brake control-The electronic brake control module controls the system functions and detects failures. It supplies voltage to the solenoid valves and pump motor.
- Brake pressure modulator-The brake pressure modulator contains the following components:
- Hydraulic pump with pump motor
- Four isolation valves
- Four dump valves
- Two traction/stability control supply valves
- Two traction/stability control isolation valves
- Pressure sensor
- High pressure accumulator
- Low pressure accumulator
- Multi-axis acceleration sensor-The yaw rate, lateral acceleration and longitudinal acceleration sensors are combined into one multi-axis acceleration sensor, external to the electronic brake control module. The electronic brake control module receives serial data message inputs from the yaw rate, lateral acceleration and longitudinal acceleration sensor and activates stability control and hill start assist function depending on multi-axis acceleration sensor input.
- Steering wheel angle sensor-The electronic brake control module receives serial data message inputs from the steering wheel angle sensor. The steering wheel angle sensor signal is used to calculate the desired yaw rate.
- Traction control switch-Traction control and stability control are manually disabled or enabled by pressing the traction control switch.
- Wheel speed sensors-The electronic brake control module sends a 12-volt reference voltage to each wheel speed sensor. As the wheel spins, the wheel speed sensor produces an alternating current square wave signal. The electronic brake control module uses the frequency of the square wave signal to calculate the wheel speed.