Mitsubishi 380. Manual — part 959

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-61

STEP 7. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
(4) Turn the ignition switch to the "ON" position.
(5) Check if the DTC is set.
(6) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC C1278 or C1279 set?

YES : Replace the hydraulic unit (integrated with

ABS-ECU). Then go to Step 8.

NO : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How to

Cope with Intermittent Malfunction

P.00-14

.

STEP 8. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
(4) Turn the ignition switch to the "ON" position.
(5) Check if the DTC is set.
(6) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC C1278 or C1279 set?

YES : Go to Step 1.
NO : The procedure is complete.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-62

DTC C1607: ABS-ECU malfunction

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.

CAUTION

Whenever the ECU is replaced, ensure that the
CAN bus lines are normal.

.

ABS DTC SET CONDITIONS

The ABS-ECU always monitors itself while the sys-
tem is working. If the ECU detects any faults, it will
set this DTC.

.

TROUBLESHOOTING HINTS (The most
likely causes for these DTCs are to set
are:)

• Malfunction of the hydraulic unit (integrated with

ABS-ECU)

Circuit drawings

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

.

DIAGNOSIS

Required Special Tools:

• MB991958: Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

STEP 1. Using diagnostic tool MB991958, diagnose the
CAN bus line.

CAUTION

To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958.
(1) Connect diagnostic tool MB991958 to the data link

connector.

(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.
NO : Repair the CAN bus line (Refer to GROUP 54C,

Diagnosis

P.54C-15

). Then go to Step 2.

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-63

STEP 2. Recheck for diagnostic trouble code.

CAUTION

To prevent damage to diagnostic tool MB991958, always
turn the ignition switch to the "LOCK" (OFF) position
before connecting or disconnecting diagnostic tool
MB991958.
(1) Turn the ignition switch to the "ON" position.
(2) Erase the DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
(4) Turn the ignition switch to the "ON" position.
(5) Check if the DTC is set.
(6) Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC C1607 set?

YES : Replace the hydraulic unit (integrated with

ABS-ECU).

NO : The procedure is complete.

DTC C1860/C1861: Power supply system (abnormal decrease or increase in voltage)

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

35DB090A

A

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-64

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 is energized by the ignition switch
(IG1) through multi-purpose fuse 23 and the
ABS-ECU terminal 18.

.

ABS DTC SET CONDITIONS

DTC C1861 will be set when the power supply volt-
age to the ABS-ECU has decreased to a predeter-
mined value or lower. C1860 will be set when the
power supply voltage to the ABS-ECU has increased
to a predetermined value or higher.

.

TROUBLESHOOTING HINTS (The most
likely causes for these DTCs are to set
are:)

Circuit drawings

• Refer to circuit diagrams GROUP-

90

• Refer to configuration diagrams GROUP-

80

Currect trouble

• Excessive electrical load

• Defective battery

• Damaged wiring harness or connector

• Malfunction of the hydraulic unit (integrated with

ABS-ECU)

• Charging system failed

.

Past trouble

Carry out diagnosis with particular emphasis on con-
nector(s) or wiring harness in the power supply cir-
cuit (terminal 18) to the ABS-ECU. For diagnosis
procedures, refer to "How to cope with past trouble"
(Refer to GROUP 00, How to Use Troubleshoot-
ing/Inspection Service Points

P.00-16

).

.

DIAGNOSIS

Required Special Tools:

• MB991958: Diagnostic Tool (MUT-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: MUT-III USB Cable

• MB991910: MUT-III Main Harness A

• MB991219: Inspection Test Harness