Mitsubishi Outlander GS45X. Manual — part 425

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-127

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

).

.

CIRCUIT OPERATION

• ASC-ECU contains the power supply circuit (terminal No.1)

for the pump motor. The pump motor is energized by the
motor switch, which is incorporated in ASC-ECU.

• The pump motor switch, which is incorporated in ASC-ECU,

is always off unless the motor and solenoid valve check is
activated when the vehicle is started.

• ASC-ECU activates the pump motor by turning on the ECU

built-in pump motor switch.

.

DTC SET CONDITIONS

This diagnostic trouble codes will be set under the cases
below:

• When the power supply voltage of the pump motor, which is

not in operation, is abnormally low for a prolonged period

• When the power supply voltage of the pump motor, which is

not in operation, is abnormally high for a prolonged period

.

PROBABLE CAUSES

Current trouble

• Fusible link malfunction

• Damaged wiring harness and connectors

• Abnormality in battery or generator

• ASC-ECU malfunction

Past trouble

• Carry out diagnosis with particular emphasis on wiring har-

ness and connector failures between the power supply cir-
cuit (A-02 ASC-ECU connector terminal No. 1) to the
ASC-ECU motor and the ground circuit (A-02 ASC-ECU
connector terminal No.16 and 47). For diagnosis proce-
dures, refer to How to treat past trouble (Refer to GROUP
00

− How to Use Troubleshooting/How to Treat Past Trou-

ble

P.00-17

).

DIAGNOSIS

Required Special Tools:

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

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-128

• 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

STEP 1. Using scan tool MB991958, diagnose the CAN bus
lines.
Use scan tool 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

P.54C-17

). On

completion, go to Step 2.

STEP 2. DTC recheck after resetting CAN bus lines
Q: Is DTC C2116 set?

YES : Go to Step 3.
NO : The procedure is complete.

STEP 3. Battery check
Refer to GROUP 54A

− Battery Test

P.54A-9

.

Q: Is the battery in good condition?

YES : Go to Step 5.
NO : Replace the battery. Then go to Step 4.

STEP 4. Charging system check
Refer to GROUP 16

− On−vehicle Service/Output Current Test

P.16-9

.

Q: Is the charging system in good condition?

YES : Go to Step 5.
NO : Repair or replace the charging system component(s).

Then go to Step 11.

STEP 5. Connector check: A-02 ASC-ECU connector
Q: Is the check result normal?

YES : Go to Step 6.
NO : Repair the defective connector. Then go to Step 11.

STEP 6. Fusible link check: Check the fusible link No.26.
Visually check for open circuit in the fusible link No.26.
Q: Is the check result normal?

YES : Go to Step 8.
NO : Go to Step 7.

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-129

STEP 7. Resistance measurement at A-02 ASC-ECU
connector
(1) Disconnect the ASC-ECU connector, connect special tool

ASC check harness (MB991997) to the harness-side
connector, and then measure the resistance at the special
tool connector side.
NOTE: Do not connect the special tool ASC check harness
(MB991997) to ASC-ECU.

(2) Disconnect the fusible link No.26.
(3) Measure the resistance between the terminal No.1 and the

body ground.

OK: No continuity

Q: Is the check result normal?

YES : Replace the fusible link No.26. Then go to Step 11.
NO : The short circuit may be present in the power supply

circuit. Repair the wiring harness between the A-02
ASC-ECU connector terminal No.1 and the fusible
link No.26, and then replace the fusible link No.26.
Then go to Step 11.

STEP 8. Voltage measurement at the A-02 ASC-ECU
connector
(1) Disconnect the ASC-ECU connector, connect special tool

ASC check harness (MB991997) to the harness-side
connector, and then measure the voltage at the special tool
connector side.
NOTE: Do not connect the special tool ASC check harness
(MB991997) to ASC-ECU.

(2) Measure the voltage between the terminal No.1 and the

body ground.

OK: Approximately system voltage

Q: Is the check result normal?

YES : Go to Step 9.
NO : The open circuit may be present in the power supply

circuit. Repair the wiring harness between the A-02
ASC-ECU connector terminal No.1 and the fusible
link No.26. Then go to Step 11.

AC611137 BW

ASC-ECU

MB991997

A-02 ASC-ECU
harness connector

Check harness

AC611137 BJ

ASC-ECU

MB991997

A-02 ASC-ECU
harness connector

Check harness

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-130

STEP 9. Resistance measurement at A-02 ASC-ECU
connector
(1) Disconnect the ASC-ECU connector, connect special tool

ASC check harness (MB991997) to the harness-side
connector, and then measure the resistance at the special
tool connector side.
NOTE: Do not connect the special tool ASC check harness
(MB991997) to ASC-ECU.

(2) Measure the resistance between the terminal No.16 and the

body ground, and between the terminal No.47 and the body
ground.

OK: Continuity exists (2

Ω or less)

Q: Is the check result normal?

YES : Go to Step 10.
NO : An open circuit may be present in the ground circuit.

Repair the wiring harness between the A-02
ASC-ECU connector terminal No.16 and the body
ground, and between the A-02 ASC-ECU connector
terminal No.47 and the body ground. Then go to Step
11.

STEP 10. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Drive the vehicle at 12 mph (20 km/h) or higher.

NOTE: The ABS warning light does not turn OFF in some
cases unless the vehicle runs at 12 mph (20 km/h) or
higher.

Q: Is DTC C2116?

YES : Replace the hydraulic unit (integrated with ASC-ECU)

(Refer to

P.35C-287

). Then go to Step 11.

NO : Intermittent malfunction (Refer to GROUP 00

− How

to Use Troubleshooting/How to Cope with Intermittent
Malfunctions

P.00-15

).

STEP 11. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Drive the vehicle at 12 mph (20 km/h) or higher.

NOTE: The ABS warning light does not turn OFF in some
cases unless the vehicle runs at 12 mph (20 km/h) or
higher.

Q: Is DTC C2116?

YES : Return to Step 1.
NO : The procedure is complete.

AC611137

ASC-ECU

MB991997

A-02 ASC-ECU
harness connector

Check harness

BK