Chrysler Concorde 1993, Service Manual, Page: 169 / 820

ANTI-LOCK BRAKE SYSTEM—TEVES MARK IV SYSTEM
INDEX
page page
ABS Brake System Diagnosis . . . . . . . . . . . . . . . 88
ABS Brake System Diagnostic Features . . . . . . . 91
ABS Computer System Service Precautions . . . . 89
ABS General Service Precautions . . . . . . . . . . . . 89
Anti-Lock Brake System Components . . . . . . . . . 80
Anti-Lock Brake System Definitions . . . . . . . . . . . 75
Anti-Lock Brakes Operation and Performance . . . 77
Anti-Lock System Fault Diagnostics . . . . . . . . . . . 79
Anti-Lock System Relays and Warning Lamps . . . 83
Controller Anti-Lock Brake (CAB) . . . . . . . . . . . . . 82
Diagnostic Connector . . . . . . . . . . . . . . . . . . . . . 83
Electronic Components . . . . . . . . . . . . . . . . . . . . 99
General Information . . . . . . . . . . . . . . . . . . . . . . . 75
Hydraulic Circuits and Valve Operation . . . . . . . . 84
Hydraulic Control Unit (HCU) . . . . . . . . . . . . . . . . 92
Hydraulic Control Unit Fluid Reservoir (FLS2) . . . 96
Major Components . . . . . . . . . . . . . . . . . . . . . . . 76
Master Cylinder and Power Booster . . . . . . . . . . 98
Mechanical Diagnostics and Service Procedures . 90
Normal Braking System Function . . . . . . . . . . . . . 75
On-Car Abs Brake System Service . . . . . . . . . . . 91
Pedal Travel Sensor . . . . . . . . . . . . . . . . . . . . . . 97
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . 103
System Diagnostic Features . . . . . . . . . . . . . . . . 78
Vehicle Performance . . . . . . . . . . . . . . . . . . . . . . 78
Warning Systems Operation . . . . . . . . . . . . . . . . 79
GENERAL INFORMATION
The purpose of the Anti-Lock Brake System (ABS)
is to prevent wheel lock-up under heavy braking con-
ditions on virtually any type of road surface. Anti-
Lock Braking is desirable because a vehicle which is
stopped without locking the wheels will retain direc-
tional stability and some steering capability. This al-
lows the driver to retain greater control of the
vehicle during heavy braking.
This section of the service manual covers the de-
scription, diagnostics, and on car service of the Teves
Mark IV Anti-Lock Brake system used on the 1993
L.H. vehicles.
The Mark IV system has several unique design fea-
tures. It can function as an Anti-Lock System only,
or as an Anti-lock and traction control system com-
bined. It contains two separate fluid reservoirs, each
with its own fluid level sensor.
The traction control feature is designed to operate
at speeds below 40 KM/H (25 MPH). Traction control
can be deactivated via the traction control switch lo-
cated on the instrument panel.
An electronic control module is used to monitor
wheel speeds and to modulate (control) hydraulic
pressure in each brake channel. The hydraulic pres-
sure is used to prevent wheel lock up during braking,
and to maintain traction at the driven wheels by re-
ducing wheel spin.
The Teves Mark IV system uses a diagonal split
hydraulic brake system. In the standard brake mode
the master cylinder primary circuit supplies pressure
to the right front and left rear wheel brakes. The
master cylinder secondary circuit supplies pressure
to the left front and right rear wheel brakes.
During an Anti-lock stop the Mark IV system uses
four channel operation. This means that during Anti-
lock operation each wheel brake is independently
controlled. By using separate hydraulic channels for
stopping each wheel. The system is able to retain di-
rectional stability and steering control while apply-
ing
maximum braking. The system provides
maximum braking even when road conditions vary.
During an Anti-Lock stop,
9
wheel lock-up
9
does not
necessarily mean that the wheel has stoped turning.
It only means that the wheel is turning slower than
the vehicle speed. This is called
9
wheel slip
9
and is
indicated in percent. 0
slip means that the wheel is rolling free and 100
slip means that the wheel is locked. The Anti-lock
System maintains an average of approximately 15
to 20
wheel slip.
ANTI-LOCK BRAKE SYSTEM DEFINITIONS
In this section of the manual several abbreviations
are used for the components that are in the Anti-
Lock Braking System They are listed below for your
reference.
•
HCU—Hydraulic Control Unit
•
CAB—Controller Anti-Lock Brake
•
ABS—Anti-Lock Brake System
•
PSI—Pounds per Square Inch (pressure)
•
WSS—Wheel Speed Sensor
NORMAL BRAKING SYSTEM FUNCTION
Under normal braking conditions, the ABS System
functions the same as a standard brake system with
a diagonally split master cylinder and conventional
vacuum assist.
If a wheel locking tendency is detected during a
brake application, the system will enter Anti-Lock
mode. During Anti-Lock Braking, hydraulic pressure
in the four wheel circuits is modulated to prevent
any wheel from locking. Each wheel circuit is de-
signed with a set of electrical valves and hydraulic
line to provide modulation, although for vehicle sta-
bility, both rear wheel valves receive the same elec-
trical signal. The system can hold, build and reduce
ANTI-LOCK BRAKE SYSTEM 5 - 75