Mitsubishi 380. Manual - part 962

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-73

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.
Use diagnostic tool MB991958 to diagnose the CAN bus lines.
(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.

Q: Is the check result satisfactory?

YES : Check and repair the power supply circuit system 

(Refer to 

P.35B-74

).   

NO :  Repair the CAN bus lines (Refer to GROUP 54C, 

Diagnosis-CAN Bus Diagnostic Chart 

P.54C-15

). 

00DB076A

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-74

INSPECTION PROCEDURE 2: Power Supply Circuit System

.

CIRCUIT OPERATION

• The ABS-ECU is energized by the ignition switch 

(IG1) through multi-purpose fuse 19 and the 
ABS-ECU terminal 18.

• If the power supply to the ABS-ECU has failed, 

diagnostic tool (MUT-III Sub Assembly) will not 
be able to communicate with it.

.

TROUBLESHOOTING HINTS (The most 
likely causes for this case:) 

• Damaged wiring harness or connector

• Defective battery

• Charging system failed

• 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

• MB991219: Inspection Test Harness

.

35DB090A

A

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-75

STEP 1. Measure the voltage at ABS-ECU connector A-02.
(1) Disconnect the connector A-02, and use special tool 

Inspection Check Harness (MB991219) to probe the wiring 
harness-side connector.

NOTE: The special tool (Inspection test harness) 
MB991219 for connector pin contact pressure should be 
used. The test probe should never be forcibly inserted, as it 
may cause a defective contact.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 18 and ground. It 

should measure approximately 12 volts (battery positive 
voltage).

Q: Is battery positive voltage (approximately 12 volts) 

present?
YES : Go to Step 3.
NO :  Go to Step 2.

35DB101A

CONNECTOR: A-02

HYDRAULIC UNIT

(WITH BUILT-IN ABS-ECU)

TEST 

HARNESS

(MB991219)

ANTI-LOCK BRAKING SYSTEM (ABS) DIAGNOSIS

ANTI-LOCK BRAKING SYSTEM (ABS)

35B-76

STEP 2. Check ABS-ECU connector A-02, junction block 
connectors C-214, C-215 and ignition switch connector 
C-308 for loose, corroded or damaged terminals, or 
terminals pushed back in the connector.

• ABS-ECU connector A-02

• Junction block connectors C-214 and C-215

• Ignition switch connector C-308

Q: Are the connectors and terminals in good condition?

YES : An open or short circuit may be present in the power 

supply line to the ABS-ECU. Repair the wiring 
harness between ABS-ECU connector A-02 terminal 
18 and ignition switch connector C-308 terminal 4. 
Then go to Step 8.

NO :  Repair or replace the damaged component(s). Refer 

to GROUP 00E, Harness Connector Inspection 

P.00E-2

. Then go to Step 8.

16DB402A

A-02 (GR)

CONNECTOR: A-02 

A-02 HARNESS CONNECTOR:

35DB041A

CONNECTORS: C-214, C-215

C-215

1
3 4

2
6

5

C-214

6

1
7

2

9

8

10

3

5

12

11

4

1314

JUNCTION BLOCK

(FRONT VIEW)

35DB042A

CONNECTOR: C-308

C-308

2

5

4

1

6

3