Mitsubishi L200. Manual - part 427

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-29

STEP 4. Connector check: A-01 ABS-ECU
connector, A-125 front wheel speed sensor (RH)
connector <C1202>, A-119 front wheel speed
sensor (LH) connector <C1207>, F-01 rear wheel
speed sensor (RH) connector <C122, 2WD
(Except High rider)> or F-10 rear wheel speed
sensor (RH) connector <C1212, 2WD (High rider),
4WD>, F-08 rear wheel speed sensor (LH)
connector <C1217, 2WD (Except High rider)> or
F-11 rear wheel speed sensor (LH) connector
<C1217, 2WD (High rider), 4WD>, C-29
intermediate connector and F-12 intermediate
connector <C1212 or C1217, 2WD (High rider),
4WD>

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Repair the defective connector. Then go to
Step 9.

STEP 5. Voltage measurement at the A-01 ABS-
ECU connector
(1) Disconnect the A-01 ABS-ECU connector, A-125

front wheel speed sensor (RH) connector
<C1202>, A-119 front wheel speed sensor (LH)
connector <C1207>, F-01 rear wheel speed
sensor (RH) connector <C1212, 2WD (Except
High rider)> or F-10 rear wheel speed sensor
(RH) connector <C1212, 2WD (High rider),
4WD>, F-08 rear wheel speed sensor (LH)
connector <C1217, 2WD (Except High rider)> or
F-11 rear wheel speed sensor (LH) connector
<C1217, 2WD (High rider), 4WD>.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between the A-01 ABS-ECU

connector terminals.

Code No.C1202 is set

• Between terminal No.6 and body earth

Code No.C1207 is set

• Between terminal No.18 and body earth

Code No.C1212 is set4

• Between terminal No.20 and body earth

Code No.C1217 is set

• Between terminal No.8 and body earth

OK: 1 V or less

Q: Is the check result normal?

YES :

Go to Step 6.

NO :

Repair the wiring harness. Then go to Step
9.

STEP 6. Resistance measurement at the A-01
ABS-ECU connector
(1) Disconnect the A-01 ABS-ECU connector, A-125

(2) Measure the resistance between the A-01 ABS-

ECU connector terminals.

Code No.C1202 is set

• Between terminal No.6 and body earth

Code No.C1207 is set

• Between terminal No.18 and body earth

Code No.C1212 is set

• Between terminal No.20 and body earth

Code No.C1217 is set

• Between terminal No.8 and body earth

OK: No continuity

Q: Is the check result normal?

YES :

Go to Step 7.

NO :

Repair the wiring harness. Then go to Step
9.

STEP 7. Check for wheel speed sensor as a
single unit
Refer to

P.35B-63

Q: Is the check result normal?

YES :

Go to Step 8.

NO :

Replace the wheel speed sensor (Refer to

P.35B-62

.). Then go to Step 9.

STEP 8. Check whether the diagnosis code is
reset.
(1) Erase the diagnosis code.
(2) Drive the vehicle at 15 km/h or more.

NOTE: The ABS warning lamp does not turn OFF
in some cases unless the vehicle runs at 15 km/h
or higher.

Q: Are diagnosis codes No.C1202, C1207, C1212 or

C1217 set?

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-30

YES :

Replace the hydraulic unit (integrated with

ABS-ECU) (Refer to

P.35B-60

.). Then go to

Step 9.

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Cope with Intermittent

Malfunctions .).

STEP 9. Check whether the diagnosis code is
reset.
(1) Erase the diagnosis code.

(2) Drive the vehicle at 15 km/h or more.

NOTE: The ABS warning lamp does not turn OFF
in some cases unless the vehicle runs at 15 km/h
or higher.

Q: Are diagnosis codes No.C1202, C1207, C1212 or

C1217 set?
YES :

Return to Step 1.

NO :

This diagnosis is complete.

Code No.C1225: Wheel speed sensor malfunction (Abnormality in tyre size)

CAUTION

• If there is any problem in the CAN bus lines,

an incorrect diagnosis code may be set. Prior
to this diagnosis, diagnose the CAN bus lines
(Refer to GROUP 54C

− CAN Bus Diagnostics

Table .).

• Before replacing the ECU, ensure that the

communication circuit is normal.

OPERATION

• A toothed ABS rotor generates a voltage pulse as

it moves across the pickup field of each wheel
speed sensor.

• The amount of voltage generated at each wheel

is determined by the clearance between the ABS
rotor teeth and the wheel speed sensor, and by
the speed of rotation.

• The wheel speed sensors transmit the frequency

of the voltage pulses and the amount of voltage
generated by each pulse to the ABS-ECU.

• The hydraulic unit assembly (integrated with

ABS-ECU) modulates the amount of braking
force individually applied to each wheel cylinder.

DIAGNOSIS CODE SET CONDITION
This diagnosis code is set when the average speed
of the front wheels differs from that of the rear wheel
by 20 % or more after the vehicle speed exceeds 30
km/h.

PROBABLE CAUSES

• Installation of different size tyres

• Damaged wiring harness or connector

• ABS-ECU malfunction

DIAGNOSIS PROCEDURE

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

Q: Is the check result normal?

YES :

Go to Step 3.

NO :

Repair the CAN bus lines (Refer to GROUP
54C

− CAN Bus Diagnostics Table .). On

completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting
CAN bus lines
(1) Erase the diagnosis code.
(2) Drive the vehicle at 30 km/h or more.

NOTE: The ABS warning lamp does not turn OFF
in some cases unless the vehicle runs at 30 km/h
or higher.

Q: Is diagnosis code No.C1225 set?

YES :

Go to Step 3.

NO :

This diagnosis is complete.

STEP 3. Check the installation condition of the
wheel and tyres.

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Install the correct size tyres. Then go to
Step 5.

STEP 4. Check whether the diagnosis code is
reset.
(1) Erase the diagnosis code.
(2) Drive the vehicle at 30 km/h or more.

NOTE: The ABS warning lamp does not turn OFF
in some cases unless the vehicle runs at 30 km/h
or higher.

Q: Is diagnosis code No.C1225 set?

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-31

YES :

Replace the hydraulic unit (integrated with

ABS-ECU) (Refer to

P.35B-60

.). Then go to

Step 5.

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Cope with Intermittent

Malfunctions .).

STEP 5. Check whether the diagnosis code is
reset.
(1) Erase the diagnosis code.

(2) Drive the vehicle at 30 km/h or more.

NOTE: The ABS warning lamp does not turn OFF
in some cases unless the vehicle runs at 30 km/h
or higher.

Q: Is diagnosis code No.C1225 set?

YES :

Return to Step 1.

NO :

The procedure is complete.

Code No.C1226: Control solenoid valve (FR) pressure holding system

Code No.C1231: Control solenoid valve (FR) pressure reducing system

Code No.C1236: Control solenoid valve (FL) pressure holding system

Code No.C1241: Control solenoid valve (FL) pressure reducing system

Code No.C1246: Control solenoid valve (RR) pressure holding system

Code No.C1251: Control solenoid valve (RR) pressure reducing system

Code No.C1256: Control solenoid valve (RL) pressure holding system

Code No.C1261: Control solenoid valve (RL) pressure reducing system

Code No.C1278: Valve relay malfunction (open circuit)

Code No.C1279: Valve relay malfunction (short circuit)

CAUTION

• If there is any problem in the CAN bus lines,

an incorrect diagnosis code may be set. Prior
to this diagnosis, diagnose the CAN bus lines
(Refer to GROUP 54C

− CAN Bus Diagnostics

Table .).

• Before replacing the ECU, ensure that the

communication circuit is normal.

OPERATION

• ABS-ECU contains the power supply circuit (ter-

minal No.1) for the solenoid valve. The solenoid
valve is energised by the valve relay, which is
incorporated in ABS-ECU.

• The valve relay, which is incorporated in ABS-

ECU, is always energising the solenoid valve
unless the initial check is in progress when the
ignition switch is turned on, or the recurrent sys-
tem check is in progress.

• ABS-ECU activates the solenoid valve by turning

on its driving transistor.

DIAGNOSIS CODE SET CONDITIONS
These diagnosis codes will be set under the cases
below.

Code No.C1226, C1231, C1236, C1241, C1246,

C1251, C1256, C1261

• The output of the each solenoid valve does not

change when the solenoid valve is "ON" and the
solenoid valve monitor is "ON"

Code No.C1278

• The solenoid valve relay monitor is "OFF" when

the solenoid valve relay is "ON"

Code No.C1279

• The solenoid valve relay monitor is "ON" when

the solenoid valve relay is "OFF"

PROBABLE CAUSES

• Damaged wiring harness or connector

• ABS-ECU malfunction

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnosis
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 .). On

completion, go to Step 2.

STEP 2. Check whether the diagnosis code is
reset.
Erase the diagnosis code.

Q: Are diagnosis codes No.C1226, C1231, C1236,

C1241, C1246, C1251, C1256, C1261, C1278 or
C1279 set?

TROUBLESHOOTING

ANTI-SKID BRAKING SYSTEM (ABS)

35B-32

YES :

Replace the hydraulic unit (integrated with

ABS-ECU) (Refer to

P.35B-60

.). Then go to

Step 3.

NO :

This diagnosis is complete.

STEP 3. Check whether the diagnosis code is
reset.
Erase the diagnosis code.

Q: Are diagnosis codes No.C1226, C1231, C1236,

C1241, C1246, C1251, C1256, C1261, C1278 or
C1279 set?
YES :

Return to Step 1.

NO :

This diagnosis is complete.

Code No.C1266: Motor malfunction (motor stick or open circuit)

Code No.C1273: Motor relay malfunction (open circuit)

Code No.C1274: Motor relay malfunction (short circuit)

MOTOR
POWER
SOURCE

MOTOR

SOLENOID VALVE

HYDRAULIC UNIT

MOTOR
POWER
SOURCE

SOLENOID
VALVE POWER
SOURCE

FUSIBLE
LINK

ABS-ECU

Solenoid Valve and Motor Power Supply Circuit

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple

ACB00768

AC501971

Connector: A-01

(B)

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