Mitsubishi L200. Manual - part 433

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-53

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Repair the CAN bus lines (Refer to GROUP 
54C, CAN Bus Diagnostics Table .). Then 
go to Step 6.

STEP 2. Connector check: A-01 ABS-ECU 
connector, C-13 intermediate connector, C-113 
combination meter connector

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair or replace it. Then go to Step 6.

STEP 3. Resistance measurement at C-113 
combination meter connector
(1) Disconnect the A-01 ABS-ECU connector and C-

113 combination meter connector.

(2) Resistance between the C-113 combination 

meter connector terminal No.19 and the body 
earth.

OK: No continuity

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

A short circuit may be present in the earth 
circuit. Repair the wiring harness between 
the A-01 ABS-ECU terminal No.16 and the 
C-113 combination meter connector 
terminal No.19. Then go to Step 6.

STEP 4. M.U.T.-III diagnosis code

Q: Is any diagnosis code set?

YES : 

Refer to Diagnosis Code Chart (Refer to 

P.35B-14

.). Then go to Step 6.

NO : 

Replace the combination meter assembly 
(Refer to GROUP 54A, Combination Meter 
Assembly .). Then go to Step 5.

STEP 5. Retest the system

Q: Turn the ignition switch to the "ON" position. Does 

the ABS warning lamp illuminate for three 
seconds, and then go out after the engine starts?
YES : 

The procedure is complete.

NO : 

Replace the hydraulic unit (integrated with 
ABS-ECU) (Refer to 

P.35B-60

.). Then go to 

Step 6.

STEP 6. Retest the system

Q: Turn the ignition switch to the "ON" position. Does 

the ABS warning lamp illuminate for three 
seconds, and then go out after the engine starts?
YES : 

The procedure is complete.

NO : 

Return to Step 1.

Inspection Procedure 3: ABS system does not operate.

COMMENT
The fail-safe function is probably cancelling ABS sys-
tem. In this case, M.U.T.-III can be used to retest 
each system by checking the diagnosis codes.

PROBABLE CAUSES

• Malfunction of the CAN bus line.

• Malfunction of the brake system.

• Malfunction of the ABS-ECU.

DIAGNOSIS

STEP 1. Hydraulic unit check
Refer to 

P.35B-57

.

Q: Is the check result normal?

YES : 

Go to Step 2.

NO : 

Connect the brake pipes correctly, repair the 
external brake lines, or replace the hydraulic 
unit.

STEP 2. Verify that the condition described by 
the customer exists.

Q: Can any faults be found with the brake operation?

YES : 

Check the brake system related 

components except the ABS system.

NO : 

The procedure is complete.

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-54

Inspection procedure 4: The initial check sound of hydraulic unit is loud.

CAUTION

When installing brake tube, match the axial 

centre of flare nut and brake tube with the centre 
of hole at the hydraulic unit side, and check that 
the fluid does not leak.
COMMENT ON TROUBLE SYMPTOM
The operation sound may be decreased by reducing 
the load at the rubber mount portion of the brake 
tube and hydraulic unit. 

PROBABLE CAUSES

• Improper installation of the hydraulic unit

• Improper installation of the brake tube

DIAGNOSIS PROCEDURE

DRIVING CHECK
(1) Turn the ignition switch from the "LOCK" (OFF) 

position to the "ON" position.

(2) When vehicle speed reaches 10 km/h, check the 

operating sound volume and compare it with that 
of the same model.

OK: The operating sound is the same vol-
ume or less by comparing with that of the 
same model.

Q: Is the check result normal?

YES : 

This diagnosis is complete.

NO : 

Carry out adjustment for hydraulic unit 
installation. (Refer to 

P.35B-57

).

DATA LIST REFERENCE TABLE

M1352011501318

The following items can be read by the M.U.T.-III 
from the ABS-ECU input data.
When the system is normal.

Item No.

Check item

Check condition

Normal condition

01

FL wheel speed sensor

Perform a test run of the vehicle Speedometer display and 

M.U.T.-III display almost agree 
with each other.

02

FR wheel speed sensor

03

RL wheel speed sensor

04

RR wheel speed sensor

05

Power supply voltage

Always

System voltage

09

*1

G-sensor

Vehicle is stopped (on a level 
surface)

0 G

Vehicle is running

-1.0 

− 1.0 G

13

Stop lamp switch

The brake pedal is depressed

ON

The brake pedal is released

OFF

63

*2

Rear diff lock switch

When rear differential lock switch 
is ON

ON

When rear differential lock switch 
is OFF

OFF

NOTE: 

.

•

*1

:4WD

•

*2

:Vehicles with rear differential lock

When the ABS-ECU shut off ABS operation.
When the diagnosis system stops the ABS-ECU, the 
M.U.T.-III display data will be unreliable.

ACTUATOR TEST REFERENCE TABLE

M1352011600851

The M.U.T.-III activates the following actuators for 
testing.

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-55

NOTE: 

.

•

When ABS-ECU is disabled, the actuator test 
cannot be performed.

•

The actuator test can be performed only when 
the vehicle is stationary. When the vehicle speed 
reaches 10km/h, the forcible actuator operation is 
disabled.

•

During actuator test, the ABS warning lamp illu-
minates, and ABS control is prohibited.

ACTUATOR TEST SPECIFICATIONS

AC504262AB

Activation Pattern

A

B

C

Start of activation

1 s

2 s

On

Off

Note
A:
B:
C:

Hydraulic pressure increases
Hydraulic pressure holds
Hydraulic pressure decreases

End of activation

Solenoid
valve

Pump
motor

Item No. Check item

Drive Contents

01

Solenoid valve for 
front-left wheel

Solenoid valves 
and pump motor in 
the hydraulic unit 
(simple inspection 
mode)

02

Solenoid valve for 
front-right wheel

03

Solenoid valve for 
rear-left wheel

04

Solenoid valve for 
rear-right wheel

CHECK AT ABS-ECU

M1352011801449

TERMINAL VOLTAGE CHECK CHART

AC501971

Connector: A-01

AU

(B)

1. Disconnect the A-01 ABS-ECU connector, and 

measure the voltages between earth terminal 
No.12 or No.24 and each respective terminal.

2. The terminal layout is shown in the illustration.
NOTE: Do not measure terminal voltage for approxi-
mately three seconds after the ignition switch is 
turned to the "ON" position. The ABS-ECU performs 
the initial check during that period.

Terminal 
No.

Check item

Checking requirements

Normal condition

1

Solenoid valve power supply

Always

Battery voltage

4

*2

Rear differential lock detection 
switch input

Rear differential lock detection switch: 
"OFF" 

Approximately 5 V

Rear differential lock detection switch: 
"ON" 

0.5 V or less

7 

Wheel speed sensor (FR) power 
supply

Ignition switch: "ON"

Approximately 
system voltage

9 

Wheel speed sensor (RL) power 
supply

Ignition switch: "ON"

Approximately 
system voltage

10

*1

G-sensor (signal)

• Ignition switch: "ON"

• Vehicle on a level surface

2.4 

− 2.6 V

13

Motor power supply

Always

Battery voltage

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-56

NOTE: 

.

•

*1

: 4WD

•

*2

: Vehicles with rear differential lock

RESISTANCE AND CONTINUITY BETWEEN 
HARNESS-SIDE CONNECTOR TERMINALS

AC501971

Connector: A-01

AU

(B)

1. Turn the ignition switch to the "LOCK" (OFF) 

position and disconnect the A-01 ABS-ECU 
connector before checking resistance and 
continuity.

2. Check the resistance and continuity between the 

terminals indicated in the table below.

3. The terminal layout is shown in the illustration.

ABS-ECU terminal No.

Signal

Normal condition

12 to body earth

Earth

Continuity exists (2 

Ω or less)

24 to body earth

Earth

Continuity exists (2 

Ω or less)

14

Brake warning lamp output

Ignition switch: "ON" (When brake 
warning lamp is ON.)

1 V or less

Ignition switch: "ON" (When the brake 
warning lamp is OFF, the brake fluid 
level is normal and the parking brake is 
"OFF" position.)

Approximately 
system voltage

16

ABS warning lamp output

Ignition switch: "ON" (When ABS 
warning lamp is ON.)

1 V or less

Ignition switch: "ON" (When ABS 
warning lamp is OFF.)

Approximately 
system voltage

19 

Wheel speed sensor (FL) power 
supply

Ignition switch: "ON"

Approximately 
system voltage

21 

Wheel speed sensor (RR) power 
supply

Ignition switch: "ON"

Approximately 
system voltage

22

*1

G-sensor (earth)

Always

0.5 V or less

25

ABS-ECU power supply(IG1)

Ignition switch: "ON" 

Battery voltage

Ignition switch: "OFF" 

1 V or less

27

Stop lamp switch input

Stop lamp switch: "ON" 

Approximately 
system voltage

Stop lamp switch: "OFF" 

1 V or less

33

*1

G-sensor (power source)

Ignition switch: "ON" 

Approximately 5 V

Terminal 
No.

Check item

Checking requirements

Normal condition