300M, Concorde, Intrepid, LHS, 1998-2004

Description & Operation


Antilock Brake System With Traction Control

This vehicle uses the MK25 Antilock braking system (ABS). This system, a combined ABS and Traction Control system is standard on some vehicles and optional on others.

This antilock brake system uses components of the base brake system, but also features the following components:

Integrated Control Unit (ICU) Includes Hydraulic Control Unit (HCU) and Antilock Brake Module (ABM)
Wheel Speed Sensors (WSS) - Four sensors (one at each wheel)

The purpose of the antilock brake system (ABS) is to prevent wheel lockup under braking conditions on virtually any type of road surface. Antilock braking is desirable because a vehicle that is stopped without locking the wheels retains directional stability and some steering capability. This allows the driver to retain greater control of the vehicle during braking.

All-Speed Traction Control

The traction control system is an all-speed traction control. All-Speed Traction Control enhances mobility and prevents wheel slip when accelerating on slippery surfaces. Depending on how slippery, an automatically activated Winter Mode feature will select lower transmission up-shift speeds. It also provides a measure of directional stability control. Using the wheel-speed sensors, it can detect excessive yaw and help keep the car on the intended course, as for instance, when accelerating around a curve.

With rear-wheel drive, All-Speed Traction Control is effective up to 85 mph (137 km/h); with AWD, All-Speed Traction Control is effective up to 45 mph (72 km/h), which is common among competitive AWD vehicles with traction control.

Electronic Stability Program

ESP® (Electronic Stability Program), which includes a Brake Assist feature, is standard on some models and optional on others. ESP aids the driver in maintaining vehicle directional stability. ESP will do whatever can be done, within the limits of available traction, to keep the car on course. ESP uses the ABS with Traction Control along with the following components to operate:

Active Brake Booster
Brake Pressure Switch
Dynamics Sensor
Travel Sensor
Steering Angle Sensor (SAS)

The Active Brake Booster is part of the Power Brake Booster. The Brake Pressure Switch is mounted to the bottom of the Master Cylinder. The Dynamics Sensor that is mounted under the center console, which is near the center of gravity of the car for effective sensing. The Travel Sensor is mounted in the Power Brake Booster. The Steering Angle Sensor is located in the steering column.

Electronic Variable Brake Proportioning

Vehicles equipped with ABS use electronic variable brake proportioning (EVBP) to balance front-to-rear braking. The EVBP is used in place of a rear proportioning valve. The EVBP system uses the ABS system to control the slip of the rear wheels in partial braking range. The braking force of the rear wheels is controlled electronically by using the inlet and outlet valves located in the integrated control unit (ICU).

EVBP activation is invisible to the customer since there is no pump motor noise or brake pedal feedback.