Mitsubishi Lancer Evolution X. Manual — part 174

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-161

PROBABLE CAUSES

• Battery failure
• Battery terminal looseness
• Fusible link malfunction
• Damaged wiring harness and connectors
• ASC-ECU malfunction
• Charging system failed

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

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

P.54C-15

). On completion,

go to Step 2.

STEP 2. DTC recheck after repairing the CAN bus line
Q: Is DTC C2101 set?

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

STEP 3. Battery terminal check
Check that the battery terminal is not loose.
Q: Is the check result normal?

YES : Go to Step 4.
NO : Securely install the battery terminal. Then go to Step

4.

STEP 4. Battery check
Refer to GROUP 54A − Battery Test

P.54A-9

.

Q: Is the battery in good condition?

YES : Go to Step 6.
NO : Charge or replace the battery, and then go to Step 5.

STEP 5. Charging system check
Refer to GROUP 16 − Charging System

P.16-7

.

Q: Is the charging system in good condition?

YES : Go to Step 6.
NO : Repair or replace the charging system component(s).

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-162

STEP 6. Connector check: A-05 ASC-ECU connector,
C-309 ETACS-ECU connector and C-315 ETACS-ECU
connector, C-103 joint connector, C-130 intermediate
connector
Q: Is the check result normal?

YES : Go to Step 7.
NO : Repair the defective connector.

STEP 7. Fusible link check: Check the fusible link No.27.
Check that the fusible link No. 27 is normal and does not
exceed the capacity.
Q: Is the check result normal?

YES : Go to Step 9.
NO : Go to Step 8.

STEP 8. Resistance measurement at A-05 ASC-ECU
connector
(1) Disconnect the connector, connect the special tool ASC

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

(2) Measure the resistance between the terminal No. 32 and

the body ground.

OK: No continuity

Q: Is the check result normal?

YES : Replace the fusible link No.27. Then go to Step 15.
NO : The short circuit may be present in the power supply

circuit. Repair the wiring harness between the A-05
ASC-ECU connector terminal No.32 and the fusible
link No.27, and then replace the fusible link No.27.
Then go to Step 15.

AC400817EN

ASC-ECU

MB991997

A-05 ASC-ECU
harness connector

Check harness

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-163

STEP 9. Voltage measurement at the A-05 ASC-ECU
connector
(1) Disconnect the connector, connect the special tool ASC

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

(2) Measure the voltage between the terminal No. 32 and the

body ground.

OK: Battery positive voltage

Q: Is the check result normal?

YES : Go to Step 10.
NO : The open circuit may be present in the power supply

circuit. Repair the wiring harness between the A-05
ASC-ECU connector terminal No.32 and the fusible
link No.27. Then go to Step 15.

STEP 10. Fusible link check: Check the fusible link No. 34.
Check that the fusible link No. 34 is normal and does not
exceed the capacity.
Q: Is the check result normal?

YES : Go to Step 12.
NO : Go to Step 11.

STEP 11. Resistance measurement at C-309 ETACS-ECU
connector
(1) Removal the fusible link No.34.
(2) Disconnect the C-309 ETACS-ECU connector, and then

measure the resistance at the connector side.

(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.34. Then go to Step 15.
NO : The short circuit may be present in the power supply

circuit. Repair the wiring harness between the C-309
ETACS-ECU connector terminal No.1 and the fusible
link No.34, and then replace the fusible link No.34.
Then go to Step 15.

AC400817CN

ASC-ECU

MB991997

A-05 ASC-ECU
harness connector

Check harness

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-164

STEP 12. Resistance measurement at fusible link No.34
and C-309 ETACS-ECU connector
(1) Disconnect the C-309 ETACS-ECU connector and fusible

link No.34, and then measure the resistance at the harness
connector side.

(2) Measure the resistance between the fusible link No.34 and

C-309 ETACS-ECU connector terminal No.1.

OK: Continuity exists (2 Ω or less)

Q: Is the check result normal?

YES : Go to Step 13.
NO : The open circuit may be present in the power supply

circuit. Repair the wiring harness between the fusible
link No.34 and C-309 ETACS-ECU connector terminal
No.1. Then go to Step 15.

STEP 13. Resistance measurement at A-05 ASC-ECU
connector
(1) Disconnect the connector, connect the special tool ASC

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

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

the body ground as well as 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 14.
NO : Repair the wiring harness.

STEP 14. Check whether the DTC is reset.
Q: Is DTC C2101 set?

YES : Replace the hydraulic unit (incorporates in

ASC-ECU). (Refer to

P.35C-298

.) Then go to Step

15.

NO : Intermittent malfunction. (Refer to GROUP 00 − How

to Cope with Intermittent Malfunction

P.00-15

.)

AC400817CO

ASC-ECU

MB991997

A-05 ASC-ECU
harness connector

Check harness