Troubleshooting Anti-Lock Brake System; Abs Indicator Light Circuit - Honda Prelude 1993 Service Manual

Troubleshooting
Anti-lock Brake System (ABS) Indicator Light
Tomporary Driving Conditions:
1. The ABS indicator light comes on and the ABS con-
trol unit memorizes the diagnostic trouble code
(DTC) under certain conditions.
NOTE: The DTCS are explained on page 19-56.
a The tire(s) adhesion is lost due to excesslve cor-
nering speed.
DTC: 5, 5-4, 5-8.
o The vehicle loses traction when starting ftom a
stuck condition on a muddy, snowY, or sandy
road.
DTC: 4-1 . 4-2, 4-4, 4-4.
a When the patking brake is applied for mofe than
30 seconds while the vehicle is being driven.
D T C : 2 - 1 .
a The vehicle is driven on an extremely rough
r o a d .
The ABS js OK. it the ABS indicator light goes off
atter the engine is testarted.
lf you receive a customer's report that the ABS in-
dicator light sometimes comes on, check the
system using the ALB checker to contirm whether
there is any trouble in the system.
S e e p a g e 1 9 - 5 1 .
The ABS indicator light will come on and the ABS
control unit will memorize a DTC when there is in-
sulficient battery voltage to the ABS control unit.
An example would be when the battery is so weak
that the car must be iump-started Aftet the battery
is sufficiently recharged, the ABS indicator light
will work normally after the engine is stopped and
restarted.
However, after recharging the battety, the DTC
must be cleared from the ABS control unit's
memory by disconnecting the ABS 82 {1 5 A) luse
in the under-hood fuse/relay box ior at least three
seconds.
ABS INDICATOR LIGHT
1 9 -5 4
1 .
ABS Indicatol Light Circuir:
CAUTION: Us6 only the digital multimet€r to chsck th.
syst6m.
The ABS indicato. light does not go on when the ig-
nition switch is turned on.
Check the following items. lf they are OK, check
the ABS control unit connectors. lf not loose or
disconnected, substitute a known-good ABS con-
trol unit and recheck:
. Blown ABS indicator light bulb.
a Open circuit in YEL wire between the No. 13
METER ('lO A) fuse in the under-dash fuse/relay
box and gauge assembly.
a Open circuit in BLU/RED wire between the
gauge assembly and ABS cont.ol unit,
a Poot ground connection between the ABS con-
trol unit and the body.
The ABS indicator light remains ON after the engine
is started. however the ABS indicator light does not
blink any DTC. Check the following items:
a Loose or poor connection of the wire harness at
the ABS control unit.
. Faulty ABS 82 (15 Al Juse in the under-hood
fuse/relay box.
a Open circuit in WHT wire between the ABS 82
(15 A) fuse in the undet-hood fuse/telay box and
ABS control unit.
a ODen circuit in BLK/YEL wire between the No. 9
R/C MIRROR (15 A) fuse in the under-dash
fuse/relay box and ABS control unit.
a Short circuit in BLU/RED wire between gauge
assembly and ABS control unil
a ODen circuit in WHT/BLU wire between alter-
nator and ABS control unit.
lf the Droblem is not found, substitute a known-
good ABS control unit and techeck whether the
ABS indicator light remains ON.