Mitsubishi Lancer Evolution X. Manual - part 190

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-225

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 U1003 set?

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

STEP 3. Connector check: A-05 ASC-ECU connector, C-46 
AWC-ECU connector, C-47 intermediate connector, C-50 
joint connector
Q: Is the check result normal?

YES : Go to Step 4.
NO :  Repair the connector, and then go to Step 7.

STEP 4. Wiring harness check between A-05 ASC-ECU 
connector terminal No. 18 and C-38 G and yaw rate sensor 
connector terminal No. 2, between A-05 ASC-ECU 
connector terminal No. 19 and C-38 G and yaw rate sensor 
connector terminal No. 3, between C-46 AWC-ECU 
connector terminal No. 9 and C-38 G and yaw rate sensor 
connector terminal No. 2, between C-46 AWC-ECU 
connector terminal No. 10 and C-38 G and yaw rate sensor 
connector terminal No. 3

• Open or short circuit check of communication circuit

Q: Is the check result normal?

YES : Go to Step 5.
NO :  Repair the wiring harness, and then go to Step 7.

STEP 5. Check whether the DTC is reset.
Q: Is DTC U1003 set?

YES : Replace the G and yaw rate sensor. (Refer to 

P.35C-304

.) Then go to Step 6.

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

to Cope with Intermittent Malfunction 

P.00-15

.)

STEP 6. Check whether the DTC is reset.
Q: Is DTC U1003 set?

YES : Replace the hydraulic unit (incorporates in 

ASC-ECU). (Refer to 

P.35C-298

.) Then go to Step 7.

NO :  The procedure is complete.

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-226

STEP 7. Check whether the DTC is reset.
Q: Is DTC U1003 set?

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

DTC U1415: Variant coding not completed

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.

• Whenever the ECU is replaced, ensure that the CAN 

bus lines are normal.

• When diagnostic trouble code No. U1415 is set in 

ASC-ECU, the diagnostic trouble code may also be set 
in ETACS-ECU. When the diagnostic trouble code is set 
in ETACS-ECU, perform the diagnosis of the diagnostic 
trouble code for ETACS-ECU first.

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

replaced, after turning the ignition switch ON and OFF 
(vehicle information from ETACS-ECU is registered), 
always perform the calibration of steering wheel sen-
sor, G and yaw rate sensor, brake fluid pressure sen-
sor, cut valve, and inlet valve.(Refer to 

P.35C-287

, 

P.35C-289

, 

P.35C-294

, and 

P.35C-295

.)

.

CIRCUIT OPERATION

ASC-ECU receives the vehicle information stored in the 
ETACS-ECU via CAN bus lines.

.

DTC SET CONDITIONS

This diagnostic trouble code is set when the variant coding for 
ETACS-ECU has not been completed.

.

PROBABLE CAUSES

• Variant coding for ETACS-ECU has not been implemented.
• 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

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-227

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 2.
NO :  Repair the CAN bus lines. (Refer to GROUP 54C − 

Troubleshooting 

P.54C-15

.) After repairing the CAN 

bus line, go to Step 5.

STEP 2. Scan tool diagnostic trouble code for other 
system
Use scan tool to check that the diagnostic trouble code B222C 
is set in the ETACS-ECU.
Q: Is any DTC set?

YES : Perform troubleshooting for the diagnostic trouble 

code that is set. Then go to Step 4.

NO :  Go to Step 3.

STEP 3. Check for diagnostic trouble codes
Q: Is DTC U1417 set?

YES : Perform the troubleshooting for diagnostic trouble 

code No. U1417. (Refer to 

P.35C-228

.)

NO :  Go to Step 4.

STEP 4. Check whether the DTC is reset.
(1) Ignition switch "LOCK" (OFF)
(2) Ignition switch "ON"
(3) Check that the ABS warning light is extinguished.
Q: Is DTC U1415 set?

YES : Replace the hydraulic unit (incorporates in 

ASC-ECU).(Refer to 

P.35C-298

.) Then go to Step 5.

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

to Cope with Intermittent Malfunction 

P.00-15

.)

STEP 5. Check whether the DTC is reset.
(1) Ignition switch "LOCK" (OFF)
(2) Ignition switch "ON"
(3) Check that the ABS warning light is extinguished.
Q: Is DTC U1415 set?

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

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-228

DTC U1417: Variant coding value invalid (includes faulty installation)

CAUTION

• If diagnostic trouble code No. U1417 is set in ASC-ECU, 

always diagnose the CAN bus lines. If there is any fault 
in the CAN bus lines, an incorrect DTC may be set.

• Whenever the ECU is replaced, ensure that the commu-

nication circuit is normal.

• When diagnostic trouble code No. U1417 is set in 

ASC-ECU, the diagnostic trouble code may also be set 
in ETACS-ECU. When the diagnostic trouble code is set 
in ETACS-ECU, perform the diagnosis of the diagnostic 
trouble code for ETACS-ECU first.

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

replaced, after turning the ignition switch ON and OFF 
(vehicle information from ETACS-ECU is registered), 
always perform the calibration of steering wheel sen-
sor, G and yaw rate sensor, brake fluid pressure sen-
sor, cut valve, and inlet valve.(Refer to 

P.35C-287

, 

P.35C-289

, 

P.35C-294

, and 

P.35C-295

.)

.

CIRCUIT OPERATION

ASC-ECU receives the vehicle information stored in the 
ETACS-ECU via CAN bus lines.

.

DTC SET CONDITIONS

ASC-ECU communicates with ETACS-ECU via CAN bus lines. 
This diagnostic trouble code is set when the vehicle information 
received from ETACS-ECU is invalid.
This diagnostic trouble code is also set when the engine control 
module sends the ASC intervention rejection (ASC not sup-
ported) signal consecutively.

.

PROBABLE CAUSES

• ETACS-ECU malfunction
• ECM malfunction
• ETACS-ECUs have been interchanged between two vehi-

cles.

• ASC-ECU malfunction
• Noise interference
• ASC-ECUs have been interchanged between two vehicles.