Description And Operation: Introduction

The ABS (anti-lock brake system) and DSC (dynamic stability control) system features a Bosch modulator, which is an integrated four-channel HCU (hydraulic control unit) and ABS module. The unit is installed in the brake hydraulic circuit between the brake master cylinder and the four brake calipers.

The ABS module is connected to the high speed CAN (controller area network) bus, and actively interacts with other vehicle system control modules and associated sensors to receive and transmit current vehicle operating information.

When required, the ABS module will actively intervene and operate the HCU during braking or vehicle maneuvers to correct the vehicle attitude, stability, traction or speed. During incidents of vehicle correction, the ABS module may also request the ECM (engine control module) to control engine power in order to further stabilize and correct the vehicle.

To provide full system functionality, the ABS and DSC system comprise the following components:

• DSC switch.
• Four wheel speed sensors.
• Steering angle sensor.
• Yaw rate and lateral acceleration sensor.
• Stoplamp switch.
• Instrument cluster indicator lamps.
• Integrated ABS module and HCU.

Two variants of ABS module are available, Bosch ESP® 8.1 and Bosch ESP® plus8.1. The Bosch ESP® plus8.1 system is fitted to vehicles with ASC (adaptive speed control) and incorporates a feature known as 'electronic brake prefill'.

The ABS provides the following brake functions that are designed to assist the vehicle or aid the driver:

• ABS.
• DSC, including TracDSC.
• CBC (corner brake control).
• EBD (electronic brake force distribution).
• ETC (electronic traction control).
• EBA (emergency brake assist).
• EDC (engine drag-torque control).
• Understeer control.
• Electronic brake prefill (vehicles with ASC only).

All the brake functions listed are automatically active when the ignition is in power mode and the engine is running. The DSC system can be selected to off using the DSC switch.