Mitsubishi Colt Ralliart. Manual — part 622

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-33

STEP 8. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-06
wheel speed sensor <RR> connector

Q: Is the check result normal?

YES :

Go to Step 9.

NO :

Repair the damaged connector.

STEP 9. Wiring harness inspection: between
A-05 ASC-ECU connector terminal No. 11, 10 and
C-06 wheel speed sensor <RR> connector
terminal No. 2, 1.

Check for short and open circuit in wheel speed sen-
sor <RR> circuit

Q: Is the check result normal?

YES :

Go to Step 12.

NO :

Repair the wiring harness.

AC601083

Connector: A-05

AB

A-05(Black)

Harness side

AC601092

Connector: B-41

AB

AC601093

Connector: C-06

AB

Harness side

C-06 (Black)

AC601083

Connector: A-05

AB

A-05(Black)

Harness side

AC601093

Connector: C-06

AB

Harness side

C-06 (Black)

Main

Index

Group

TOC

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-34

STEP 10. Connector check: A-05 ASC-ECU
connector, B-41 intermediate connector, C-17
wheel speed sensor <RL> connector

Q: Is the check result normal?

YES :

Go to Step 11.

NO :

Repair the damaged connector.

STEP 11. Wiring harness check: between A-05
ASC-ECU connector terminal No. 11, 10 and C-17
wheel speed sensor <RL> connector terminal No.
2, 1.

Check for short and open circuit in wheel speed sen-
sor <RL> circuit

Q: Is the check result normal?

YES :

Go to Step 12.

NO :

Repair the wiring harness.

STEP 12. Diagnosis code recheck

Q: Is diagnosis code No. C1222 set?

YES :

Replace the ASC-ECU.

NO :

Intermittent malfunction (Refer to GROUP
00

− How to Cope with Intermittent

Malfunction

P.00-13

.)

AC601083

Connector: A-05

AB

A-05(Black)

Harness side

AC601092

Connector: B-41

AB

AC601094

Connector: C-17

AB

C-17(Black)

Harness side

AC601083

Connector: A-05

AB

A-05(Black)

Harness side

AC601094

Connector: C-17

AB

C-17(Black)

Harness side

Main

Index

Group

TOC

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-35

Code No. C1225: Wheel speed sensor system (sensor output error)

CAUTION

If there is any problem in the CAN bus lines, an
incorrect diagnosis code may be set. Prior to this
diagnosis, always diagnose the CAN bus lines.

OPERATION

• The wheel speed sensor is a kind of a pulse gen-

erator. It consists of magnetic encoders (a plate
on which north and south pole sides of the mag-
nets are arranged alternately) for detecting the
wheel speed which rotates at the same speed of
the wheels and speed sensors. This sensor out-
puts frequency pulse signals in proportion to the
wheel speed.

• The pulse signals, which the wheel speed sensor

creates, are sent to ASC-ECU. ASC-ECU uses
the frequency of the pulse signals to determine
the wheel speed.

Wheel Speed Sensor 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

FRONT WHEEL SPEED SENSOR

REAR WHEEL SPEED SENSOR

(LH)

(LH)

(RH)

(RH)

ASC-ECU

Main

Index

Group

TOC

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-36

DIAGNOSIS CODE SET CONDITIONS

The ASC-ECU monitors the signals from each wheel
speed sensor. If any faults below is found in this sen-
sor signal, the ECU will set the relevant diagnosis
code. When the abnormal wheel is identified, the
diagnosis code No. C1201, C1206, C1211, or C1216
is set.

• Missing sensor signal

• Sensor signal, which will not be created under

normal operation

• Significant difference among the wheel speed

sensor signals

• Continuous ABS or ASC control for one minute or

more

PROBABLE CAUSES

Current trouble

• Improper installation of the wheel speed sensor

• Adhesion of foreign materials on the wheel speed

detection magnetic encoder

• Deformation of the wheel speed detection mag-

netic encoder

• Excessive gap between the wheel speed sensor

and the wheel speed detection magnetic encoder

• Damaged wiring harness and connectors

• Malfunction of the wheel speed sensor

• ASC-ECU malfunction

Past trouble

• The following conditions may occur.

• Right or/and left wheels are rotated.

• Unstable vehicle attitude

• External noise interference

DIAGNOSTIC PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use the 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
54D, Troubleshooting

P.54D-13

.) On

completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting
CAN bus lines

Q: Is the relevant diagnosis code No. C1225 set?

YES :

Go to Step 3.

NO :

This diagnosis is complete.

STEP 3. Wheel speed sensor installation state
check
Check the installation state (sensor disconnection,
loose mounting bolts, etc.) of the wheel speed sen-
sor for every wheel.

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Reinstall the wheel speed sensor correctly.

STEP 4. Check for wheel speed sensor as a
single unit
Refer to

P.35B-81

.

Q: Is the check result normal?

YES :

Go to Step 5.

NO :

Replace the wheel speed sensor.

STEP 5. Check for wheel bearing looseness
NOTE: Loose wheel bearing may increase the gap
between the wheel speed sensor and the wheel
speed detection magnet encoder. Check each wheel
bearing for looseness.

• Front: Refer to GROUP 26 − On-vehicle Service

P.26-5

.

• Rear: Refer to GROUP 27A − On-vehicle Service

P.27-3

.

Q: Is the check result normal?

YES :

Go to Step 6.

NO <when the relevant wheel is front> :

Replace

the wheel bearing. (Refer to GROUP 26

−

Front Axle Hub

P.26-13

.)

NO <when the relevant wheel is rear> :

Replace

the rear hub assembly. (Refer to GROUP
27A

− Rear Axle Hub

P.27-6

.)

Main

Index

Group

TOC