Mitsubishi L200. Manual — part 445

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-36

STEP 7. Check the front hub for looseness.
NOTE:

.

•

If the wheel bearing or front hub or axle shaft
bearing are loose, the gap between the wheel
speed sensor and ABS rotor may become exces-
sive.

•

Check the front hub, which diagnosis code indi-
cates, for looseness. (Refer to GROUP 26, On-
vehicle service

−

Wheel bearing axial play check

.).

Q: Is the check result normal?

YES :

Go to Step 8.

NO :

Replace the front hub assembly (Refer to
GROUP 26, Front axle hub assembly .).
Then go to Step 13.

STEP 8. Check the ABS rotor.
Check the ABS rotor (FR), which diagnosis code
indicates, for foreign material or deformation.

Q: Is the check result normal?

YES :

Go to Step 9.

NO :

If the ABS rotor (FR) is contaminated with
foreign material, clean it. If the front hub
assembly is deformed, replace it (Refer to
GROUP 26, Front axle hub assembly .).
Then go to Step 13.

STEP 9. Connector check: A-48 ASTC-ECU
connector, A-125 front wheel speed sensor (RH)
connector.

Q: Is the check result normal?

YES :

Go to Step 10.

NO :

Repair the defective connector. Then go to
Step 13.

STEP 10. Voltage measurement at the A-48
ASTC-ECU connector
(1) Disconnect the A-48 ASTC-ECU connector, the

A-125 front wheel speed sensor (RH) connector.

(2) Measure the voltage between the A-48 ASTC-

ECU connector terminal No.7 and body earth.

OK: 1V or less

Q: Is the check result normal?

YES :

Go to Step 11.

NO :

Repair the harness wire. Then go to Step
13.

STEP 11. Resistance measurement at the A-48
ASTC-ECU connector
(1) Disconnect the A-125 front wheel speed sensor

(RH) connector, and measure the resistance at
the harness connector side.

(2) Disconnect the A-48 ASTC-ECU connector.
(3) Measure the resistance between the A-48 ASTC-

ECU connector terminal No.7 and body earth.

OK: No continuity

Q: Is the check result normal?

YES :

Go to Step 12.

NO :

Repair the harness wire. Then go to Step 13
.

STEP 12. 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: Is the diagnosis code No.C1201 set?

YES :

Replace the hydraulic unit (integrated with

ASTC-ECU) (Refer to

P.35C-140

.). Then go

to Step 13.

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Cope with Intermittent

Malfunctions .).

STEP 13. 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: Is the diagnosis code No.C1201 set?

YES :

Return to Step 1.

NO :

This diagnosis is complete.

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-37

Code No.C1206: Wheel speed sensor (FL) (signal short circuit)

ACB00772

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

Wheel Speed Sensor Circuit

ASTC-ECU

FRONT WHEEL
SPEED SENSOR
(LH)

FRONT WHEEL
SPEED SENSOR
(RH)

REAR WHEEL
SPEED SENSOR
(LH)

REAR WHEEL
SPEED SENSOR
(RH)

AC800980

AG

Connector: A-48

(B)

AC502545AS

Connector: A-119

A-119 (B)

A-119 Harness
connector
(harness side)

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-38

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 wheel speed sensor transmit the frequency

of the pulses to the ASTC-ECU.

• The hydraulic unit assembly (integrated with

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

DIAGNOSIS CODE SET CONDITION
Diagnosis code No.C1206 is set if any abnormal volt-
age from the wheel speed sensor is detected without
the outputs of the codes No.C1205 or C1207.

PROBABLE CAUSES

Current trouble

• Damaged wiring harness and connectors

• Teeth lack or clogging of the ABS rotor

• Malfunction of the front hub assembly

• Noise interference

• Wheel speed sensor malfunction

• ASTC-ECU malfunction

Past trouble

• Carry out diagnosis with particular emphasis on

wiring harness and connector failures between
ASTC-ECU and the wheel speed sensor. For
diagnosis procedures, refer to How to treat past
trouble (GROUP 00

− How to Cope with Intermit-

tent Malfunctions .).

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 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: Is the diagnosis code No.C1206 set?

YES :

Go to Step 3.

NO :

This diagnosis is complete.

STEP 3. M.U.T.-III diagnosis code
Check that the diagnosis codes No.C1205 or C1207
is also set.

Q: Are the diagnosis codes No.C1205 or C1207 also

set?
YES :

Perform the diagnosis for the diagnosis

codes No.C1205 or C1207 (Refer to

P.35C-

25

,

P.35C-50

.).

NO :

Go to Step 4.

STEP 4. M.U.T.-III data list
Check the following data list (Refer to

P.35C-131

.).

• Item No.01: FL wheel speed sensor

Q: Is the check result normal?

YES :

Go to Step 12.

NO :

Go to Step 5.

STEP 5. Check for wheel speed sensor (FL)
installation
Check how the wheel speed sensor (FL) is installed
correctly (Disconnection of wheel speed sensor (FL),
loose mounting bolt, etc.).

Q: Is the check result normal?

YES :

Go to Step 6.

NO :

Reinstall the wheel speed sensor (FL)
correctly (Refer to

P.35C-141

). Then go to

Step 13.

STEP 6. Check for wheel speed sensor (FL)
output current
Refer to

P.35C-135

.

Q: Is the check result normal?

YES :

Go to Step 7.

NO :

Replace the wheel speed sensor (FL)
(Refer to

P.35C-141

.). Then go to Step 13.

TROUBLESHOOTING

ACTIVE STABILITY & TRACTION CONTROL SYSTEM (ASTC)

35C-39

STEP 7. Check the front hub for looseness.
NOTE:

.

•

If the wheel bearing or front hub or axle shaft
bearing are loose, the gap between the wheel
speed sensor and ABS rotor may become exces-
sive.

•

Check the front hub, which diagnosis code indi-
cates, for looseness. (Refer to GROUP 26, On-
vehicle service

−

Wheel bearing axial play check

.).

Q: Is the check result normal?

YES :

Go to Step 8.

NO :

Replace the front hub assembly (Refer to
GROUP 26, Front axle hub assembly .).
Then go to Step 13.

STEP 8. Check the ABS rotor.
Check the ABS rotor (FL), which diagnosis code indi-
cates, for foreign material or deformation.

Q: Is the check result normal?

YES :

Go to Step 9.

NO :

If the ABS rotor (FL) is contaminated with
foreign material, clean it. If the front hub
assembly is deformed, replace it (Refer to
GROUP 26, Front axle hub assembly .).
Then go to Step 13.

STEP 9. Connector check: A-48 ASTC-ECU
connector, A-119 front wheel speed sensor (LH)
connector.

Q: Is the check result normal?

YES :

Go to Step 10.

NO :

Repair the defective connector. Then go to
Step 13.

STEP 10. Voltage measurement at the A-48
ASTC-ECU connector
(1) Disconnect the A-48 ASTC-ECU connector, the

A-119 front wheel speed sensor (LH) connector,.

(2) Measure the voltage between the A-48 ASTC-

ECU connector terminal No.19 and body earth.

OK: 1V or less

Q: Is the check result normal?

YES :

Go to Step 11.

NO :

Repair the harness wire. Then go to Step
13.

STEP 11. Resistance measurement at the A-48
ASTC-ECU connector
(1) Disconnect the A-119 front wheel speed sensor

(LH) connector, and measure the resistance at
the harness connector side.

(2) Disconnect the A-48 ASTC-ECU connector.
(3) Measure the resistance between the A-48 ASTC-

ECU connector terminal No.19 and body earth.

OK: No continuity

Q: Is the check result normal?

YES :

Go to Step 12.

NO :

Repair the harness wire. Then go to Step 13
.

STEP 12. 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: Is the diagnosis code No.C1206 set?

YES :

Replace the hydraulic unit (integrated with

ASTC-ECU) (Refer to

P.35C-140

.). Then go

to Step 13.

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Cope with Intermittent

Malfunctions .).

STEP 13. 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: Is the diagnosis code No.C1206 set?

YES :

Return to Step 1.

NO :

This diagnosis is complete.