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Mitsubishi Lancer Evolution VI. Manual - part 58

REAR AXLE –

Troubleshooting <AYC>

27-26

Item No.

Normal value

Checking requirements

Check item

Steer sensor (ST-N)

Steering wheel position
Ignition switch: ON

Neutral position

Ignition switch: ON

90 deg. turned
from neutral
position

OFF

Steer sensor (ST-1)

Steering wheel position: Turn slowly counterclock-
wise.
Ignition switch: ON

ON and OFF are
indicated alternate-
ly.

Steer sensor (ST-2)

Steering wheel position: Turn slowly clockwise.
Ignition switch: ON

ON and OFF are
indicated alternate-
ly.

Stop lamp switch

Accelerator pedal position
Ignition switch: ON

Depressed

Ignition switch: ON

Released

OFF

Pressure switch

Forced activation No.13 or
No.14 is being executed.

Electric pump in
operation

Low

Electric pump
not in operation

High

ABS monitor

ABS not in operation

OFF

REAR AXLE –

Troubleshooting <AYC>

27-27

ACTUATOR TEST REFERENCE TABLE

The following items can be tested by driving the corresponding actuator forcibly using the MUT-

Item No.

Check item

Checking requirements

Normal value

Air bleeding

Supply current to proportioning
valve in accordance with steering
angle to operate directional valve.

No air is to be bled from the
bleeder plug on the torque transfer
differential.

Oil level check

Let the directional valve operate to
left and right 20 times.

To be checked by oil level in
reservoir tank.

Electric pump operation

Let the electric pump operate for 5
seconds.

Operation sounds of the electric
pump are to be heard.

Clutch operation (left)

Let the directional valve operate to
supply the maximum pressure to the
left clutch.

The operation conditions are to be
checked by the speed difference
between left and right rear wheels
with the wheels raised. For details,
refer to AYC Operation Check on
P.27-34.

Clutch operation (right)

Let the directional valve operate to
supply the maximum pressure to the
right clutch.

The operation conditions are to be
checked by the speed difference
between left and right rear wheels
with the wheels raised. For details,
refer to AYC Operation Check on
P.27-34.

Control OFF

Turn off the electric pump relay to
deactivate AYC control.

During the test run, some
differences are to be recognized in
running behaviors between when
the system is ON and when it is
OFF.

NOTE
(1) The actuator test is feasible only when the following requirements are all satisfied.

All of inputs from four wheel speed sensors show 20 km/h or lower.

No system failure is registered.

The steering angle is within

30 deg. from the neutral position.

(2) The actuator test comes to an end when either of the following conditions is met since the forced

actuation is canceled.

Either of inputs from four wheel sensors shows higher than 20 km/h (with exception of Item
No.15 “Control OFF”).

Some trouble with the system is registered.

Forced activation time expires.

MUT-

is removed.

The clear key of MUT-

is operated.

REAR AXLE –

Troubleshooting <AYC>

27-28

CHECK AT AYC-ECU TERMINALS

TERMINAL VOLTAGE LISTING

The voltage is to be measured across each terminal and ground terminal.

Fig. below shows the arrangement of the terminals.

Terminal
No.

Check item

Check requirement

Normally

Lateral acceleration sensor

Ignition switch: ON

2.4 – 2.6 V
(horizontal position)

Longitudinal acceleration
sensor ground
Lateral acceleration sensor
ground

At all times

0 V

Longitudinal acceleration
sensor

Ignition switch: ON

2.4 – 2.6 V
(horizontal position)

Steer sensor (ST-2)

Engine: Idle speed
Turn steering wheel slowly.

0 V

↔

approx. 3 V

flashing

Steer sensor (ST-1)

Engine: Idle speed
Turn steering wheel slowly.

0 V

↔

approx. 3 V

flashing

FR wheel speed

Vehicle stationary

1 V or less

Forward vehicle slowly.

0 – 5 V

FL wheel speed

Vehicle stationary

1 V or less

Forward vehicle slowly.

0 – 5 V

RR wheel speed

Vehicle stationary

1 V or less

Forward vehicle slowly.

0 – 5 V

FL wheel speed

Vehicle stationary

1 V or less

Forward vehicle slowly.

0 – 5 V

Diagnosis selection input

When MUT

-II

is connected

1 V or less

When MUT

-II

is disconnected

System voltage

Stop lamp switch

Ignition switch:
ON

Stop lamp switch: ON

System voltage

Stop lamp switch: OFF

1 V or less

12*

ABS monitor

When ABS monitor is activated

System voltage

When ABS monitor is deactivated

1 V or less

REAR AXLE –

Troubleshooting <AYC>

27-29

Terminal
No.

Normally

Check requirement

Check item

Steer sensor (ST-N)

Engine:
Idle speed

Steering wheel: Neutral position

0.5 V or less

Idle speed

Steering wheel: Turned 90

from

neutral position

2.5 – 3.5 V

TPS

Ignition switch:
ON

Accelerator pedal: Fully closed

0.3 – 1.0 V

Accelerator pedal: Fully open

4.5 – 5.0 V

Diagnosis data input/output

When MUT-

is connected

Serial communica-
tion with MUT-

When MUT-

is disconnected

1 V or less

Idle position switch

Ignition switch:
ON

Accelerator pedal: Fully closed

2 V or less

Accelerator pedal: Fully open

4.5 – 5.0 V

Accumulator pressure
switch

Ignition switch:
ON

Accumulator internal pressure:
Low

2 V or less

Accumulator internal pressure:
High

System voltage

ECU ground

At all times

0 V

AYC-ECU power supply

Ignition switch: ON

System voltage

Ignition switch: OFF

0 V

AYC motor relay

Ignition switch:
ON

When motor is energized

System voltage

When motor is deenergized

2 V or less

AYC warning lamp

Ignition switch:
ON

When lamp is OFF

System voltage

When lamp is ON

2 V or less

Directional control valve
(right)

Ignition switch:
ON

Right clutch: ON

System voltage

(right)

Right clutch: OFF

0 V

Proportioning valve

Ignition switch:
ON

AYC-ON

0 V to system volt-
age

AYC-OFF

0 V

ECU backup power supply

At all times

System voltage

Directional control valve
(left)

Ignition switch:
ON

Left clutch: ON

System voltage

(left)

Left clutch: OFF

0 V

ECU ground

At all times

0 V

NOTE
*1: Indicates the vehicles with ABS.

Content .. 56 57 58 59 ..