Mitsubishi Evolution X. Manual - part 796

DIAGNOSIS

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-191

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-14

.) 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 4.
NO :  Repair or replace the charging system component(s), 

and then go to Step 17.

STEP 4. Charging system check
Refer to GROUP 16 

− Output Current Test 

P.16-8

.

Q: Is the charging system in good condition?

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

and then go to Step 17.

DIAGNOSIS

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-192

STEP 5. Voltage measurement at A-05 ASC-ECU connector
(1) Disconnect the connector, connect the ASC check harness 

(Special tool: 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: System voltage

Q: Is the check result normal?

YES : Go to Step 7.
NO :  Go to Step 6.

STEP 6. Connector check: A-05 ASC-ECU connector
Q: Is the check result normal?

YES : An open or 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.

NO  :  Repair the defective connector, and then go to Step 

17.

STEP 7. Check of fuse No. 17 and fusible link No. 34
Visually check for open circuit in the fuse No. 17 and the fusible 
link No. 34.
Q: Is the check result normal?

YES : Go to Step 8.
NO :  Replace the fuse No. 17 or the fusible link No. 34.

AC400817CN

ASC-ECU

MB991997

A-05 ASC-ECU 
harness connector

Check harness

DIAGNOSIS

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-193

STEP 8. Voltage measurement at the A-05 ASC-ECU 
connector
(1) Disconnect the connector, connect the ASC check harness 

(Special tool: 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: System voltage

Q: Is the check result normal?

YES : Go to Step 15.
NO :  Go to Step 9.

STEP 9. Connector check: C-309 ETACS-ECU connector
Q: Is the check result normal?

YES : Go to Step 10.
NO  :  Repair the defective connector.

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

harness-side connector.

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

body ground.

OK: System voltage

Q: Is the check result normal?

YES : Go to Step 11.
NO :  Repair the wiring harness between C-309 

ETACS-ECU connector terminal No. 1 and the fusible 
link No. 34.

STEP 11. Connector check: C-315 ETACS-ECU connector
Q: Is the check result normal?

YES : Go to Step 12.
NO  :  Repair the defective connector.

AC400817CN

ASC-ECU

MB991997

A-05 ASC-ECU 
harness connector

Check harness

DIAGNOSIS

TSB Revision

ACTIVE SKID CONTROL SYSTEM (ASC)

35C-194

STEP 12. Voltage measurement at the C-315 ETACS-ECU 
connector
(1) Without disconnecting the connector, measure by 

backprobing.

(2) Measure the voltage between the terminal No.4 and the 

body ground.

OK: System voltage

Q: Is the check result normal?

YES : Go to Step 14.
NO :  Go to Step 13.

STEP 13. Connector check: C-103 joint connector, C-130 
intermediate connector
Q: Is the check result normal?

YES : Go to Step 14.
NO  :  Repair the defective connector.

STEP 14. Wiring harness check between A-05 ASC-ECU 
connector terminal No. 2 and C-315 ETACS-ECU connector 
terminal No. 4

• Open or short circuit check

Q: Is the check result normal?

YES : Go to Step 15.
NO  :  Repair the wiring harness.

STEP 15. Resistance measurement at A-05 ASC-ECU 
connector
(1) Disconnect the connector, connect the ASC check harness 

(Special tool: 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) 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 17.
NO :  Go to Step 16.

AC400817CO

ASC-ECU

MB991997

A-05 ASC-ECU 
harness connector

Check harness