Mitsubishi Outlander GS45X. Manual - part 459

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-263

CAUTION

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

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

− CAN Bus Line Diagnostic Flow 

P.54C-10

).

• Whenever ECU is replaced, ensure that the CAN bus 

lines are normal.

• When the hydraulic unit (integrated with ASC-ECU) is 

replaced, always carry out the calibration of the steer-
ing wheel sensor, the G and yaw rate sensor and brake 
fluid pressure sensor (Refer to 

P.35C-282

, 

P.35C-283

 

and 

P.35C-284

).

.

OPERATION

• The slope gradient may be low.

• The vehicle is not completely stationary.

• A failure may have occurred in the calibration of the G and 

yaw rate sensor or brake fluid pressure sensor.

• The parking brake switch may be seized, which causes the 

HSA to fail to start the operation.

• A problem (noise interference) may have occurred in the 

CAN bus line, resulting in an improper communication with 
ASC-ECU or each ECU.

NOTE: 

.

•

The HSA does not work even when the wheel speed sensor 
output pulse (vehicle moved) while the vehicle is parked.

•

The HSA is affected by the loading conditions and vehicle 
posture at the occurrence of phenomenon. When checking 
the HSA operation in actual driving, carry out the check on 
the vehicle with one occupant (driver) only.

.

PROBABLE CAUSES

• Improper installation of the G and yaw rate sensor

• G and yaw rate sensor malfunction

• Calibration failure of the G and yaw rate sensor

• Calibration failure of the brake fluid pressure sensor

• Seizure of the parking brake switch

• Malfunction of wheel speed sensor

• Malfunction of transmission range switch

• Malfunction of ETACS-ECU

• Malfunction of hydraulic unit (integrated with ASC-ECU)

• Wiring harness or connector failure of CAN bus line

• Damaged wiring harness and connectors

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: Vehicle Communication Interface (V.C.I.)

• MB991827: M.U.T.-III USB Cable

• MB991910: M.U.T.-III Main Harness A

• MB991997: ASC check harness

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-264

STEP 1. HSA operation check
Check if the HSA works with one occupant (driver) only in the 
vehicle.
Q: Is the check result normal?

YES : The procedure is complete.
NO :  Go to Step 2.

STEP 2. Parking brake check
With the parking brake not pulled, check if the brake warning 
light is off.
Q: Is the check result normal?

YES  : Go to Step 3.
NO :  Carry out Inspection Procedure 3 "Brake warning light 

stays ON with the parking brake lever released (ABS 
warning light is OFF)" (Refer to 

P.35C-219

).

STEP 3. Using scan tool MB991958, diagnose the CAN bus 
line.
Use scan tool to diagnose the CAN bus lines.
Q: Is the check result normal?

YES : Go to Step 4.
NO :  Repair the CAN bus lines (Refer to GROUP 54C 

− 

CAN Bus Diagnostics Table 

P.54C-17

). Then go to 

Step 13.

STEP 4. Using scan tool MB991958, check DTC
Use scan tool MB991958 to check the DTC for the ASC sys-
tem.
Q: Is the DTC set?

YES : Carry out the diagnosis for the diagnostic trouble 

code (Refer to 

P.35C-18

).

NO :  Go to Step 5.

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-265

STEP 5. Using scan tool MB991958, check the data list
Check the following data list (Refer to 

P.35C-270

).

• Pulled up parking brake lever.

• Move the selector lever to the "R", "D", "N" and "P" position. 

Q: Is the check result normal?

YES  : Go to Step 6.
NO <Item No. 120> : Carry out the Inspection procedure 3 

"Brake Warning Light Stays ON with the Parking 
Brake Lever Released (ABS warning light is OFF)" 
(Refer to 

P.35C-219

), and then go to Step 13.

NO <Item No. 70, 71> : Go to Step 11.

STEP 6. Using scan tool MB991958, check the data list
Check the following data list under curb weight condition or one 
occupant (driver) only in the vehicle, on a flat road.(Refer to 

P.35C-270

)

• Item 09: G sensor

• Item 12: Yaw rate sensor

Q: Is the check result normal?

YES : Go to Step 9
NO :  Go to Step 7

STEP 7. Connector check: A-02 ASC-ECU connector, C-26 
G and yaw rate sensor
Q: Is the check result normal?

YES : Go to Step 8.
NO :  Repair the connector, and then go to Step 13.

Item No.

Item name

Normal 
condition

120

Parking brake 
switch (Input)

ON

Item No. Item name

Normal condition

70

Target gear

• "R"

• Selector lever:"R" 

position

• "D"

• Selector lever:"D" 

position

• "P"

• Selector lever:"P" 

position

• "N"

• Selector lever:"N" 

position

71

Actual gear

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-266

STEP 8. Check the harness wire between C-26 G and yaw 
rate sensor connector terminal No. 3, 2 and  A-02 ASC-ECU 
connector No. 18, 19.

• Check the communication lines for open circuit and short 

circuit.

Q: Is the check result normal?

YES : Go to Step 9.
NO :  Repair the wiring harness, and then go to Step 13.

STEP 9. G and yaw rate sensor installation check
Check that the G and yaw rate sensor is installed correctly.
Q: Is the check result normal?

YES : Carry out the calibration of the G and yaw rate sensor 

(Refer to 

P.35C-282

). Then go to Step 10

NO :  Reinstall the G and yaw rate sensor correctly (Refer 

to 

P.35C-290

), and then go to Step 13.

STEP 10. Using scan tool MB991958, check the data list
Check the following data list (Refer to 

P.35C-270

).

• Item 10: Master cylinder pressure

Q: Is the check result normal?

YES  : Go to Step 11
NO :  Carry out the calibration of the brake fluid pressure 

sensor (Refer to 

P.35C-282

). Then go to Step 13

STEP 11. Using scan tool MB991958, check the DTC
Use scan tool MB991958 to check that the DTC is set in the 
TCM.
Q: Is the DTC set?

YES : Carry out the diagnosis for the DTC (Refer to GROUP 

23A 

− Diagnostic Trouble Code Chart 

P.23A-29

 

<CVT> or GROUP 23C 

− Diagnostic Trouble Code 

Chart 

P.23C-27

 <A/T>).

NO :  Go to Step 12.

STEP 12. Retest the system.
Check if the HSA works with one occupant (driver) only in the 
vehicle.
Q: Is the check result normal?

YES : If a trouble is solved, it is determined that there is an 

intermittent malfunction such as poor engaged 
connector(s) or open circuit (Refer to GROUP 00 

− 

How to Use Troubleshooting/How to Cope with 
Intermittent Malfunctions 

P.00-15

).

NO :  Replace the hydraulic unit (integrated with ASC-ECU) 

(Refer to 

P.35C-287

).