Mitsubishi Colt Ralliart. Manual - part 621

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-29

STEP 22. 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 23.

NO : 

Repair the wiring harness.

STEP 23. ABS warning lamp OFF recheck
Drive the vehicle until the vehicle speed reaches 
30km/h and check that the ABS warning lamp goes 
out.

Q: Does the ABS warning lamp extinguish?

YES : 

Go to Step 25.

NO : 

Replace the ASC-ECU, and then go to Step 
24.

STEP 24. ABS warning lamp OFF recheck
Drive the vehicle until the vehicle speed reaches 
30km/h and check that the ABS warning lamp goes 
out.

Q: Does the ABS warning lamp extinguish?

YES : 

Go to Step 25.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Cope with Intermittent 

Malfunction 

P.00-13

.)

STEP 25. Diagnosis code recheck
Recheck if the diagnosis code is set.
(1) Erase the diagnosis code.
(2) Ignition switch: LOCK (OFF) position
(3) Ignition switch: ON

Q: Is the diagnosis code No.C1201, C1206, C1211 or 

C1216 set?
YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Cope with Intermittent 

Malfunction 

P.00-13

.)

NO : 

This diagnosis is complete.

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-30

Code No. C1222: Wheel speed sensor system (abnormal power supply voltage)

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.

DIAGNOSIS CODE SET CONDITIONS

The wheel speed sensors are energised by 
ASC-ECU. If an abnormality occurs in this power 
supply voltage, this diagnosis code is set.

PROBABLE CAUSES

• Short-circuited wheel speed sensor circuit and 

power supply circuit

• ASC-ECU malfunction

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.

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-31

STEP 2. Diagnosis code recheck after resetting 
CAN bus lines

Q: Is the diagnosis code No. C1222 set?

YES : 

Go to Step 3.

NO : 

This diagnosis is complete.

STEP 3. Voltage measurement: A-05 ASC-ECU 
connector

(1) Disconnect the connector, connect the ABS 

check harness (Special tool: MB991984) to the 
harness-side connector, and measure the voltage 
at the special tool connector side.
NOTE: Do not connect the special tool to 
ASC-ECU.

(2) Ignition switch: ON
(3) Measure the voltage between the power supply 

and signal terminals in the wheel speed sensor 
circuit and body earth.

OK: 0 V

Q: Is the check result normal?

YES : 

Go to Step 12.

NO (Not normal at the terminal No. 29 or 28) : 

Go 

to Step 4.

NO (Not normal at the terminal No. 34 or 13) : 

Go 

to Step 6.

NO (Not normal at the terminal No. 30 or 8) : 

Go to 

Step 8.

NO (Not normal at the terminal No. 11 or 10) : 

Go 

to Step 10.

STEP 4. Connector check: A-05 ASC-ECU 
connector, A-29 wheel speed sensor <FR> 
connector

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the damaged connector.

AC601083

Connector: A-05

AB

A-05(Black)

Harness side

AC601085AB

MB991984

Check connector

ASC-ECU

ASC-ECU harness connector

Wheel speed sensor 
position

Checking terminal
Power 
supply 
terminal

Signal 
terminal

Right front wheel

No. 29

No. 28

Left front wheel

No. 34

No. 13

Right rear wheel

No. 30

No. 8

Left rear wheel

No. 11

No. 10

AC601083

Connector: A-05

AB

A-05(Black)

Harness side

AC601084

Connector: A-29

AB

Harness 
side

A-29(black)

Main

Index

Group

TOC

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-32

STEP 5. Wiring harness inspection: between 
A-05 ASC-ECU connector terminal No. 29, 28 and 
A-29 wheel speed sensor <FR> connector 
terminal No. 2, 1.

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

Q: Is the check result normal?

YES : 

Go to Step 12.

NO : 

Repair the wiring harness.

STEP 6. Connector check: A-05 ASC-ECU 
connector, A-06 wheel speed sensor <FL> 
connector

Q: Is the check result normal?

YES : 

Go to Step 7.

NO : 

Repair the damaged connector.

STEP 7. Check the harness wire between A-05 
ASC-ECU connector terminal No. 34, 13 and A-06 
wheel speed sensor <FL> connector terminal No. 
2, 1.

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

AC601084

Connector: A-29

AB

Harness 
side

A-29(black)

AC601083

Connectors: A-05, A-06

AC

A-05(Black)

A-05:
Harness side

A-06: Harness side

A-06 (Black)

AC601083

Connectors: A-05, A-06

AC

A-05(Black)

A-05:
Harness side

A-06: Harness side

A-06 (Black)

Main

Index

Group

TOC