Mitsubishi Lancer (4A9 engine). Manual - part 70

 

  Index      Mitsubishi     Mitsubishi Lancer (4A9 engine) 12GS41 & 44S - service repair manual

 

Search            

 

 

 

 

 

 

 

 

 

Content   ..  68  69  70  71   ..

 

 

Mitsubishi Lancer (4A9 engine). Manual - part 70

 

 

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-133

YES : 

Troubleshoot for the relevant diagnosis 

code, and then go to Step 5.

NO : 

Go to Step 5.

STEP 5. Check whether the diagnosis code is 
reset.
Erase the diagnosis code.

Q: Is Code No. U1004 set?

YES : 

Replace the hydraulic unit (integrated with 

ASC-ECU) (Refer to 

P.35C-185

.), and then 

go to Step 6.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Cope with Intermittent 

Malfunctions .).

STEP 6. Check whether the diagnosis code is 
reset.
Erase the diagnosis code.

Q: Is diagnosis code No.U1004 set?

YES : 

Return to Step 1.

NO : 

This diagnosis is complete.

Code No. U0125 G and yaw rate sensor message time-out error/message error

G and Yaw Rate Sensor Circuit

G AND YAW RATE SENSOR

ASC-ECU

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     SI : Silver

ACB02567

AC612691

AO

Connector: A-58 <LHD>

A-58 (B)

AC701238 AF

Connector: A-58 <RHD>

A-58 (B)

AC612705

Connector: C-137 <LHD>

CG

C-137 (B)

AC701122

Connector: C-137 <RHD>

BL

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-134

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 ).

• Whenever ECU is replaced, ensure that the 

CAN bus lines are normal.

• Do not drop or shock the G and yaw rate sen-

sor.

• When the G and yaw rate sensor is replaced, 

always carry out calibration to make ASC-
ECU learn the neutral point (Refer to 

P.35C-

182

).

• When the hydraulic unit (integrated with ASC-

ECU) is replaced, always carry out the calibra-
tion of the steering wheel sensor, the G and 
yaw rate sensor and brake fluid pressure sen-
sor (Refer to 

P.35C-182

P.35C-183

 an

P.35C-

184

).

OPERATION
The G and yaw rate sensor outputs the signal to 
ASC-ECU via the special CAN bus lines.

DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set when the ASC-ECU can-
not receive the signal from the G and yaw rate sen-
sor although there is no abnormality in ASC-ECU 
supply voltage.

PROBABLE CAUSES

• Wiring harness or connector failure for the spe-

cial CAN bus lines between ASC-ECU and the G 
and yaw rate sensor

• G and yaw rate sensor malfunction

• ASC-ECU malfunction

• External noise interference

• Connector disconnected or improperly connected

• Stretched or broken wires

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 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

Q: Is diagnosis code No. U0125 set?

YES : 

Go to Step 3.

NO : 

This diagnosis is complete.

STEP 3. Connector check: A-58 ASC-ECU 
connector, C-137 G and yaw rate sensor 
connector

Q: Is the check result normal?

YES : 

Go to Step 4.

NO : 

Repair the connector, and then go to Step 7.

STEP 4. Wiring harness check between A-58 
ASC-ECU connector terminal No. 18 and C-137 G 
and yaw rate sensor connector terminal No. 3 as 
well as between A-58 ASC-ECU connector 
terminal No. 19 and C-137 G and yaw rate sensor 
connector terminal No. 2

• Check the communication circuit for open and 

short circuit.

Q: Is the check result normal?

YES : 

Go to Step 5.

NO : 

Repair the wiring harness, and then go to 
Step 7.

STEP 5. Diagnosis code recheck
Erase the diagnosis code.

Q: Is diagnosis code No. U0125 set?

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-135

YES : 

Replace the G and yaw rate sensor (Refer 

to 

P.35C-189

). Then go to Step 6.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use Troubleshooting/How to 

Cope with Intermittent Malfunctions ).

STEP 6. Diagnosis code recheck
Erase the diagnosis code.

Q: Is diagnosis code No. U0125 set?

YES : 

Replace the hydraulic unit (integrated with 

ASC-ECU). (Refer to 

P.35C-185

). Then go 

to Step 7.

NO : 

This diagnosis is complete.

STEP 7. Diagnosis code recheck
Erase the diagnosis code.

Q: Is diagnosis code No. U0125 set?

YES : 

Return to Step 1.

NO : 

This diagnosis is complete.

Code No. U0401 Engine signal malfunction detected

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 ).

• If diagnosis code No.U0401 is set in ASC-

ECU, always diagnose the CAN bus line. If 
there is any fault in the CAN bus lines, an 
incorrect diagnosis code may be set. In this 
case, the set diagnosis code is not highly reli-
able.

• Before replacing the ECU, ensure that the 

communication circuit is normal.

OPERATION
Engine-related signals are sent or received to and 
from between ASC-ECU and engine ECU via CAN 
bus lines.

DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set when the engine ECU 
malfunction has been detected.

PROBABLE CAUSES

• Malfunction of engine system

• Malfunction of engine ECU

• Malfunction of ASC-ECU

• External noise interference

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 5.

STEP 2. M.U.T.-III diagnosis code
Use M.U.T.-III to check that any diagnosis code other 
than the code No.U0401 is set in ASC-ECU.

Q: Is the diagnosis code set?

YES : 

Troubleshoot the relevant diagnosis code, 

and then go to Step 5.

NO : 

Go to Step 3.

STEP 3. M.U.T.-III other system diagnosis code
Use M.U.T.-III to check that the diagnosis code is set 
by the engine ECU.

Q: Is the diagnosis code set?

YES : 

Troubleshoot the relevant diagnosis code, 

and then go to Step 5.

NO : 

Go to Step 4.

STEP 4. Check whether the diagnosis code is 
reset.
Erase the diagnosis code.

Q: Is diagnosis code No.U0401 set?

YES : 

Replace the hydraulic unit (integrated with 

ASC-ECU) (Refer to 

P.35C-185

), and then 

go to Step 5.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use Troubleshooting/How to 

Cope with Intermittent Malfunctions ).

STEP 5. Check whether the diagnosis code is 
reset.
Erase the diagnosis code.

Q: Is diagnosis code No.U0401 set?

YES : 

Return to Step 1.

NO : 

This diagnosis is complete.

TROUBLESHOOTING

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-136

Code No. U0428 Communication error in steering wheel sensor

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 ).

• If diagnosis code U0428 is set in ASC-ECU, 

always diagnose the CAN bus line. If there is 
any fault in the CAN bus lines, an incorrect 
diagnosis code may be set. In this case, the 
set diagnosis code is not highly reliable.

• Before replacing the ECU, ensure that the 

communication circuit is normal.

• When the hydraulic unit (integrated with ASC-

ECU) is replaced, always carry out the calibra-
tion of the steering wheel sensor, the G and 
yaw rate sensor and brake fluid pressure sen-
sor (Refer to 

P.35C-182

P.35C-183

 an

P.35C-

184

).

OPERATION
The steering wheel sensor outputs the steering 
wheel status to ASC-ECU via the CAN bus lines.

DIAGNOSIS CODE SET CONDITIONS
This diagnosis code is set when ASC-ECU has 
detected the communication error in the steering 
wheel sensor.

PROBABLE CAUSES

• Steering wheel sensor malfunction

• ASC-ECU malfunction

• External noise interference

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 : 

Replace the steering wheel sensor (Refer to 

P.35C-190

). Then go to Step 2.

NO : 

Repair the CAN bus lines (Refer to GROUP 
54C 

− CAN Bus Diagnostics Table ). On 

completion, go to Step 3.

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

Q: Is diagnosis code No.U0428 set?

YES : 

Replace the hydraulic unit (integrated with 

ASC-ECU) (Refer to 

P.35C-185

).

NO : 

This diagnosis is complete.

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

Q: Is diagnosis code No.U0428 set?

YES : 

Return to Step 1.

NO : 

This diagnosis is complete.

 

 

 

 

 

 

 

Content   ..  68  69  70  71   ..