Mitsubishi Lancer Evolution X. Manual - part 203

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-277

28

ASC/TCL off switch

ASC OFF switch not operated 
(ASC control is available)

ON

When ASC OFF switch is 
operated (pressed shortly) (ASC 
control is prohibited)

OFF

When ASC OFF switch is 
operated (pressed and held for 
15 seconds or more) (ASC OFF 
control is prohibited by fail-safe.)

ON

45

SAS OK flag

When the learning is completed

Comp

When the learning is not 
completed

Not Comp

When the steering wheel sensor 
is faulty

SAS fail
SAS fail&Not Comp

65

Engine Speed

When the accelerator pedal is 
depressed (engine started)

The tachometer display and 
the scan tool display almost 
agree with each other.

66

Engine torque

Displays the engine torque.

67

APS sensor

Displays the accelerator pedal 
opening angle.

68

Allow ESP torque request Engine torque intervention is 

permitted

Allow

70

Target gear

The shift lever is operated

Displays the shift lever 
position.

71

Actual gear

72

Master cylinder pressure 
Offset

Master cylinder pressure sensor 
correction amount at the master 
cylinder pressure sensor 
calibration

-8 to 8 bar

73

Lateral G sensor offset

Lateral G sensor correction 
amount at G and yaw rate sensor 
calibration

-0.15 to 0.15 G

86

Ignition switch

Ignition switch is "ON" position

ON

87

Ignition switch (input)

Ignition switch is "ON" position

ON

Ignition switch is "START" 
position

START

88

Vehicle speed

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

scan tool display almost agree 
with each other.

91

Brake pressure sensor

The brake pedal is depressed.

Pressed

The brake pedal is released.

Not pressed

96

G sensor offset

Longitudinal G sensor correction 
amount at G and yaw rate sensor 
calibration

-0.3 to 0.3 G

97

Yaw rate sensor offset

Yaw rate sensor correction 
amount at G and yaw rate sensor 
calibration

-6.0 to 6.0 deg/s

Item No.

Check item

Check conditions

Normal conditions

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-278

2. System shutdown by ECU 

While ASC-ECU is disabled by the diagnostic 
function, the scan tool displayed data is different 
from the actual measurement.

ACTUATOR TEST REFERENCE TABLE

M1355001600172

Using scan tool, the following actuators can be forc-
ibly operated:
NOTE: 

.

•

ABS, TCL, and stability control are operated by 
ASC-ECU.

•

When ASC-ECU is disabled due to the fail-safe 
function, the actuator test cannot be performed.

•

The actuator test can be performed only when 
the vehicle is stationary.

•

While the actuator test is performed, the ABS 
warning light flashes at a rate of 2 Hz.

•

After the actuator test has been performed, the 
brake warning light, ABS warning light, ASC ON 
indicator light, and ASC OFF indicator light illumi-
nate until the ignition switch is turned to ON again 
or the communication between scan tool and 
ASC-ECU is terminated.

.

105

Power supply voltage (input)

System voltage (10 to 18 V 
ASC operable range)

120

Parking brake switch 
(input)

When the parking brake lever is 
pulled up.

ON

When the parking brake lever is 
released.

OFF

128

ASC/TCL off switch

When the ASC OFF switch is 
pressed.

ON

When the ASC OFF switch is not 
pressed.

OFF

129

FL wheel 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

130

FR wheel 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

131

RL wheel 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

132

RR wheel 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

133

FL wheel cylinder pres. 
offset

Wheel cylinder fluid pressure 
sensor correction amount

-8 to 8 bar

134

FR wheel cylinder pres. 
offset

135

RL wheel cylinder pres. 
offset

136

RR wheel cylinder pres. 
offset

Item No.

Check item

Check conditions

Normal conditions

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-279

Actuator test specifications

.

Operation pattern of items 01 to 08 

Item No.

Check item

Driven component

01

FL wheel ABS drive

Solenoid valve for the corresponding 
channel of the hydraulic unit and pump 
motor (simplified inspection mode)

02

FR wheel ABS drive

03

RL wheel ABS drive

04

RR wheel ABS drive

05

FL wheel TCL drive

06

FR wheel TCL drive

07

RL wheel TCL drive

08

RR wheel TCL drive

09

Engine TCL drive

Outputs the engine torque control signal 
(engine torque = 0 N⋅ m) to the engine 

ECU for three seconds.

AC400776

1second

2 seconds

Approx. 0.05
second

Approx. 0.01
second

AB

End

Scan tool actuator test
(Item No.05, 06, 07, 08) start

End

Increase in pressure

Steady pressure

Reduction in pressure

Increase in pressure

Steady pressure

Reduction in pressure

Drive

Stop

Cut valve,
Suction valve
(TCL/Skid control)

Solenoid valve
(ABS)

Pump motor

Scan tool actuator test
(Item No.01, 02, 03, 04) start

DIAGNOSIS

TSB Revision

ACTIVE STABILITY CONTROL SYSTEM (ASC)

35C-280

CHECK AT ECU TERMINALS

M1355001700191

.

TERMINAL VOLTAGE CHECK

Required Special Tool:
MB991997: ASC Check Harness
1. Operate the lock lever as shown in the figure to disconnect 

the ASC-ECU wiring harness connector.

2. Connect special tool ASC Check Harness (MB991997) to 

measure the voltage between each check connector 
terminal and the ground terminal (No. 16 or 47).

AC708791

AB

Lock lever

AC401192 AG

ASC-ECU

MB991997

A-05 ASC-ECU 
harness connector

Check harness