Mitsubishi Lancer Evolution X. Manual - part 202

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-273

STEP 2. Resistance measurement at C-209 steering wheel 
sensor connector.
(1) Disconnect C-209 steering wheel sensor connector and 

measure the resistance available at the wiring harness side 
of the connector.

(2) Check the continuity between C-209 steering wheel sensor 

connector terminal No.5 and body ground.

OK: Continuity exists (2 Ω or less)

Q: Is the check result normal?

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

STEP 3. Check the wiring harness between C-209 steering 
wheel sensor connector terminal No.5 and the body 
ground.

• Check the ground wires for open circuit.

Q: Is the check result normal?

YES : If a trouble is solved, it is determined that there is an 

intermittent malfunction such as poor engaged 
connector(s) or open circuit (Refer to GROUP 00 − 

How to Cope with Intermittent Malfunction 

P.00-15

).

NO :  Repair the wiring harness.

STEP 4. Connector check: C-309 ETACS-ECU connector, 
C-317 ETACS-ECU connector
Q: Is the check result normal?

YES : Go to Step 5.
NO  :  Repair the damaged connector.

STEP 5. Voltage measurement at C-309 ETACS-ECU 
connector
(1) Disconnect C-306 ETACS-ECU connector and measure the 

voltage available at the wiring harness side of the 
connector.

(2) Measure the voltage between C-309 ETACS-ECU 

connector terminal No.1 and body ground.

OK: Battery positive voltage

Q: Is the check result normal?

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

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

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STEP 6. Check the wiring harness between fusible link No. 
34 and C-309 ETACS-ECU connector terminal No.1.

• Check the power supply lines (battery power supply) for 

open circuit and short circuit.

Q: Is the check result normal?

YES : If a trouble is solved, it is determined that there is an 

intermittent malfunction such as poor engaged 
connector(s) or open circuit (Refer to GROUP 00 − 

How to Cope with Intermittent Malfunction 

P.00-15

).

NO :  Repair the wiring harness.

STEP 7. Measure the voltage at the C-209 steering wheel 
sensor connector.
(1) Disconnect C-209 steering wheel sensor connector and 

measure the voltage at the wiring harness side of the 
connector.

(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between the terminal No.2 and the 

body ground.

OK: Approximately battery positive voltage

Q: Is the check result normal?

YES : Go to Step 10.
NO :  Go to Step 8.

STEP 8. Check the fuse No.12.
Visually check for open circuit in fuse No.12.
Q: Is the check result normal?

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

circuit. Check the wiring harness between the C-209 
steering wheel sensor connector terminal No.2 and 
the C-317 ETACS-ECU connector terminal No.5, and 
repair if necessary. And then replace the fuse No.12.

DIAGNOSIS

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ACTIVE STABILITY CONTROL SYSTEM (ASC)

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STEP 9. Check the wiring harness between C-209 steering 
wheel sensor connector terminal No.2 and C-317 
ETACS-ECU connector terminal No.5.

• Check the power supply lines (battery power supply) for 

open circuit.

Q: Is the check result normal?

YES : Go to Step 10.
NO :  Repair the wiring harness between the C-209 steering 

wheel sensor connector terminal No.2 and the C-317 
ETACS-ECU connector terminal No.5.

STEP 10. Using scan tool MB991958, check the ETACS 
system data list
Check the input signal of IG1 relay.

• Turn the ignition switch to the ON position.

OK: Normal condition is displayed.

Q: Is the check result normal?

YES : Replace the steering wheel sensor.
NO :  Refer to GROUP 54A - ETACS − Input Signal 

Procedure 2 "The ignition switch (IG1) signal is not 
received." 

P.54A-704

.

Item No.

Item name

Normal 
condition

Item 254

IG voltage

System voltage

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DATA LIST REFERENCE TABLE

M1355001500216

The following items of ECU input data can be read 
using the scan tool.
1. The system is normal.

Item No.

Check item

Check conditions

Normal conditions

01

FL wheel speed sensor

Perform a test run of the vehicle. The speedometer display and 

scan tool display almost agree 
with each other. <Vehicle 
stopped: Approximately 0.7 
km/h (1.1 mph)>

02

FR wheel speed sensor

03

RL wheel speed sensor

04

RR wheel speed sensor

05

Power supply voltage

System voltage (10 to 18 V 
ASC operable range)

07

Brake switch (input)

The brake pedal is depressed.

ON

The brake pedal is released.

OFF

08

Lateral G sensor (+: left 
turn, -: right turn)

Vehicle stopped (level)

-0.11 to 0.11 G

Running

-1 to 1 G

09

G sensor (+: deceleration, 
-: acceleration)

Vehicle stopped (level)

-0.11 to 0.11 G

Running

-1 to 1 G

10

Master cylinder pressure

The brake pedal is depressed.

Increases by the amount of 
the brake pedal depression.

The brake pedal is released.

-3 to 3 bar

11

Steering angle (+: left turn, 
-: right turn)

Vehicle stopped (Steering wheel 
in neutral position)

-6 to 6 deg

Running

Nearly the same as the 
steering wheel operation angle 
<-720 to 720 deg (ASC-ECU 
normal detection value)>

When removed from vehicle 
(Steering wheel sensor as a 
single unit)

Nearly the same as the 
steering wheel operation angle 
<-850 to 850 deg (Sensor 
normal value as a single unit)>

12

Yaw rate sensor (+: left 
turn, -: right turn)

Vehicle stopped (level)

-3.6 to 3.6 deg/s

Running

-100 to 100 deg/s

14

Brake switch

The brake pedal is depressed.

ON

The brake pedal is released.

OFF

15

Emission test mode

Emission test mode: ON

ON

Emission test mode: OFF

OFF

26

Brake fluid pressure 
switch

Brake fluid level is lower than the 
"LOWER" marking.

Low

Brake fluid level is higher than 
the "LOWER" marking.

Normal