System Diagnosis; Introduction; Overview - Subaru Legacy Reference Booklet

AN
INTRODUCTION
TO
ABS 5.3 SYSTEM DIAGNOSIS
V E R V I E W
The ABS 5.3 is a four-sensor, four channel
system. It controls the front wheels inde-
pendently during ABS braking. It controls
the rear wheels as a pair, as appropriate for
whichever of the two wheels is turning
more slowly.
It was introduced in 1996 on Legacy vehi-
cles equipped with ABS. More recently, an
updated system, the ABS 5.3i, has been
introduced. The 5.3i is used on the 1998
Forester, late 1997 Legacy, and late 1997
Impreza vehicles equipped with ABS.
The ABS 5.3 system has improved self-
diagnostics and trouble code memory, and
it can communicate with OBD-I1 testers,
such as the New Select Monitor.
(1)
ABS control module and hydraulic (5) G sensor
(2) Proportioning valve
(6)
ABS warning light
control unit (ABSCM&H/U)
(9)
Wheel cylinder
(1 0) Transmission control moi
AT vehicle)
(11) Brake switch
(1 2) Master cylinder
le (only
(3)
Diagnosis connector
(7)
Tone wheel
(4) Data link connector (for SUBARU (8) ABS sensor
select monitor)
ABS 5.3i
System
4
V i d e o R e f e r e n c e B o o k l e t