Mitsubishi Lancer Evolution X. Manual - part 184

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-201

DTC SET CONDITIONS

This diagnostic trouble code is set under the cases below.

• Trouble information stored in the EEPROM is not reliable.
• ASC-ECU power supply is shut down while the trouble 

information is being written to EEPROM.

.

PROBABLE CAUSES

• Disconnection of the ASC-ECU connector or the battery ter-

minal when the ignition switch is ON

• Loose battery terminal
• Abnormality in battery
• Damaged wiring harness and connectors
• ASC-ECU malfunction

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 − 

Troubleshooting 

P.54C-15

.) After repairing the CAN 

bus line, go to Step 2.

STEP 2. DTC recheck after repairing the CAN bus line
Q: Is DTC C1608 set?

YES : Go to Step 3.
NO :  This diagnosis 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 :  Go to Step 4.

STEP 4. Charging system check
Refer to GROUP 16 − Output Current Test 

P.16-8

.

Q: Is the charging system in good condition?

YES : Replace the battery. Then go to Step 15.
NO :  Repair or replace the charging system component(s), 

and then go to Step 15.

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-202

STEP 5. Connector check: A-05 ASC-ECU connector, 
C-103 joint connector, C-130 intermediate connector, C-309 
ETACS-ECU connector, C-315 ETACS-ECU connector
Q: Is the check result normal?

YES : Go to Step 6.
NO  :  Repair the defective connector, and then go to Step 

15.

STEP 6. Check of fusible link No. 27
Visually check for open circuit in the fusible link No. 27.
Q: Is the check result normal?

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

STEP 7. 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 voltage 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, and then go to Step 

15.

NO :  An short circuit may be present in the power supply 

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

AC400817EO

ASC-ECU

MB991997

A-05 ASC-ECU 
harness connector

Check harness

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-203

STEP 8. Voltage 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 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 9.
NO :  An open circuit may be present in the power supply 

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

STEP 9. Check of fusible link No.34
Visually check for open circuit in the fusible link No.34.
Q: Is the check result normal?

YES : Go to Step 11.
NO :  Go to Step 10.

STEP 10. Resistance measurement at C-309 ETACS-ECU 
connector
(1) Disconnect the connector, and measure the resistance at 

the harness connector side.

(2) 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, and then go to Step 

15.

NO :  An short circuit may be present in the power supply 

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

STEP 11. Check of fuse No.17
Visually check for open circuit in the fuse No.17.
Q: Is the check result normal?

YES : Go to Step 13.
NO :  Go to Step 12.

AC400817CN

ASC-ECU

MB991997

A-05 ASC-ECU 
harness connector

Check harness

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-204

STEP 12. 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 voltage at the special tool 
connector side.
NOTE: Do not connect the special tool to ASC-ECU.

(2) Remove fuse No.17.
(3) Measure the resistance between the terminal No.2 and the 

body ground.

OK:No continuity

Q: Is the check result normal?

YES : Replace the fuse No.17, and then go to Step 15.
NO :  An short circuit may be present in the power supply 

circuit. Repair the wiring harness between C-315 
ETACS-ECU connector terminal No.4 and the A-05 
ASC-ECU connector terminal No.2. Replace the fuse 
No.17, and then go to Step 15.

STEP 13. 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.2 and the 

body ground.

OK: Battery positive voltage

Q: Is the check result normal?

YES : Go to Step 14.
NO :  An open circuit may be present in the power supply 

circuit. Repair the wiring harness between A-05 
ASC-ECU connector terminal No.2 and the fusible 
link No.34, and then go to Step 15.

AC400817EP

ASC-ECU

MB991997

A-05 ASC-ECU 
harness connector

Check harness

AC400817CN

ASC-ECU

MB991997

A-05 ASC-ECU 
harness connector

Check harness