Mitsubishi 1989 Galant, Service Manual

Page: 1155 / 1273

SERVICE BRAKES Anti-lock Braking System Troubleshooting
TROUBLESHOOTING
Confirm condition in the following way and diagnose accordingly.
the ABS warning light illuminate as described
elow up to the time the engine starts?
1) When the ignition key is turned to the “ON”
position, the ABS warning light blinks four times
for approximately second due to the ABS ECU
(as a self check of the valve relays is performed),
and goes out and stays out.
W ith the ignition key in the “START” position,
power to the ABS ECU is interrupted and the
ABS warning light remains lit because the valve
relay is OFF.
(3) When the ignition key is turned from the “START’
position to the “ON” position, the ABS warning
l i g h t b l i n k s f o u r t i m e s f o r a p p r o x i m a t e l y
second (during this time a recheck of the valve
relays is performed), and then goes out and
stays out.
4
1000
ABS
ABS warning
light
ON
I
OFF
Ignition
ACC, LOCK
Yes
CONTINUE TO NEXT PAGE
No
No. Trouble condition
ABS warning light does not light up at all.
1
warning
light
Ignition
ACC,
ON
OFF
LOCK
When the key
IS
turned to the
“ON” position, it remains lighted.
ABS
ON ,
l Short in ECU warning light drive circuit
l Malfunction of ECU
ignition
ACC.
Major causes
l
ABS warning light bulb is burnt out.
l
Open in ABS warning light electrical
circuit (check for blown fuse)
l
Fail safe is functioning due to ECU
board diagnostic
Does not illuminate when ignition key is
in “START” position.
l
Malfunction of valve relay
l Break in harness between ABS warn-
ing light and HU
l Break in harness between HU and
Remedy
Check, using flow
chart A (Refer to
Check, using flow
chart (Refer to
Check, using flow
chart (Refer to
TSB Revision