Mitsubishi 380. Manual - part 956
ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS
ANTI-LOCK BRAKING SYSTEM (ABS)
35B-49
CAUTION
If there is any problem in the CAN bus lines, an
incorrect diagnostic trouble code may be set.
Prior to this diagnosis, diagnose the CAN bus
lines.
NOTE: If the ABS-8 ECU or the active wheel
speed sensor are disconnected, or if the wiring is
an open/ short circuit, the ABS 8 ECU will shut
off power supply to the respective wheel speed
sensor. All other wheel speed sensors will oper-
ate normally. To restore the power supply, the
ignition switch must be turned to the "OFF" posi-
tion then to the "ON" position again.
.
CIRCUIT OPERATION
• The ABS-ECU contains the power supply circuit
(terminal 2) for the pump motor. The pump motor
is energized by a MOSFET driver, which is inte-
grated in the ABS-ECU.
• A MOSFET driver, which is integrated in the
ABS-ECU, is always off unless the motor sole-
noid valve check is activated when the vehicle is
started.
• The ABS-ECU activates the pump motor by turn-
ing on the ECU built-in MOSFET driver when the
ABS is working.
.
ABS DTC SET CONDITIONS
These diagnostic trouble codes will be set under the
cases below.
DTC C1266: Motor system (seizure)
• This DTC is set when the ECU determines the
pump motor is not running smoothly (i.e. motor
seizure) by the motor relay ON/OFF.
DTC C1273: Motor relay problem (stuck off)
• If the ABS-ECU determines that the motor is not
running after the MOSFET driver is turned on, the
ECU determines that the motor relay is stuck off,
and sets this DTC.
DTC C1274: Motor relay problem (stuck on)
• If the ABS-ECU determines that the motor is run-
ning after the MOSFET driver is turned off, the
ECU determines that the motor relay is stuck on,
and sets this DTC.
.
TROUBLESHOOTING HINTS (The most
likely causes for these DTCs are to set
are:)
Current trouble
• Damaged wiring harness or connector
• Malfunction of the hydraulic unit (integrated with
ABS-ECU)
.
FUSIBLE LINK
ABS (motor supply)
No. 3 (30 A)
RELAY BOX
35DB095A