Mitsubishi 1989-1993 GALANT Service Manual page 1167

SERVICE BRAKES
When the following diagnostic trouble codes are displayed "11 FL SPD SENSOR" "12
FR SPD SENSOR" "13 RL SPD SENSOR" "14 RR SPD SENSOR"
The ABS ECU detects breaks in the wheel speed
sensor wire. This diagnostic trouble code is output
if the wheel speed sensor signal is not input (or
short circuited) or if its output is low when starting
to drive or while driving.
When diagnostic trouble code
[Explanation]
This diagnostic trouble code is output when there is
an abnormality (other than broken wire or short cir-
cuit) in the wheel speed sensor output signal while
driving.
[Hint]
The following can be considered as the cause of the
wheel speed sensor output abnormality.
Distortion of rotor, teeth missing
l
Low frequency noise interference when sensor
l
harness wire is broken
Noise interference in sensor signal
l
standard value or when amplitude modulation is
over the standard value., using an oscilloscope to
measure the wave shape of the wheel speed
sensor output signal is very effective.
Loose wheel bearing
l
REVERSE SIDE DATA LlNK
Braking System Troubleshooting
"15
SENSOR FAULT" is displayed
FRONT
(LEFT SIDE) (RIGHT SIDE)
FRONT SIDE
CONNECTOR
TSB Revision
[Hint]
In addition to a broken wire/short circuit in the wheel
speed sensor, also check whether the sensor gap is
too large, rotor teeth are missing, sensor harness
wire is temporarily broken, or sensor harness and
body connector are not properly inserted.
Temporarily broken wire in sensor harness
l
Sensor harness and body connector are not
l
properly inserted.
NOTE
(1) If contact is poor, check the sensor cable by
bending and lightly stretching it.
(2) If there is currently no trouble and if abnormality
in the displayed sensor circuit cannot be dis-
covered since values are normal even when
checked, turn the ignition switch OFF and
re-execute the driving test. Try replacing the
ABS ECU only if the same diagnostic trouble
code is output at this time.
(If it is difficult to recreate the trouble, there is a
possibility of speed sensor trouble recurring even if
the ECU is replaced.)
SPEED SENSOR
REAR
(LEFT SIDE) (RIGHT SIDE)
GND
ABS
ECU