MITSUBISHI LANCER EVOLUTION VI 1999 Workshop Manual

REAR AXLE – Troubleshooting <AYC>27-25
DATA LIST REFERENCE TABLE
The following items can be read by t01he MUT-

from the ECU input data.
Item No.
Check itemChecking requirementsNormal value
01Front-right wheel speedPerform a test run.Vehicle speeds
displayed on the
02Front-left wheel speed
displayed on the
speedometer and
MUTIIare identi03Rear-right wheel speedMUT-II are identi-
cal.
04Rear-left wheel speed
05Front-right wheel speed
(0.2 km/h)
06Front-left wheel speed (0.2
km/h)
07Rear-right wheel speed
(0.2 km/h)
08Rear-left wheel speed (0.2
km/h)
10Vehicle speed
11System voltageIgnition switch: ONBattery voltage
15TPS openingAccelerator pedal position/Igni-
tion switch: ON
Fully closed300 – 1000mV
tion switch: ON
Partially openGradually increases
from the above val-
ue.
Fully open4500 – 5000mV
19Longitudinal acceleration
sensor
Vehicle stands on level ground2.4 – 2.6V
sensor
Perform a test run.Reading fluctuates
up or down with 2.5V
as its center.
20Lateral acceleration sensorVehicle stands on level ground2.4 – 2.6V
Perform a test run.Reading fluctuates
up or down with 2.5V
as its center.
22Steering wheel operationSteering wheel turning direction
Ignition switch: ON90 deg. clock-
wiseR90 deg
90 deg counter-
clockwiseL90 deg
23Steering wheel turning
angular velocity
Steering wheel position
Ignition switch: ON
Not turned0 deg/s
angular velocityIgnition switch: ON
TurnedReading varies ac-
cording to turning
speeds.
45Idle position switchAccelerator pedal position
Ignition position: ON
Not depressedON
Ignition position: ON
DepressedOFF

REAR AXLE – Troubleshooting <AYC>27-26
Item No.Normal value Checking requirements Check item
46Steer sensor (ST-N)Steering wheel position
Ignition switch: ON
Neutral positionON
Ignition switch: ON
90 deg. turned
from neutral
positionOFF
47Steer sensor (ST-1)Steering wheel position: Turn slowly counterclock-
wise.
Ignition switch: ONON and OFF are
indicated alternate-
ly.
48Steer sensor (ST-2)Steering wheel position: Turn slowly clockwise.
Ignition switch: ONON and OFF are
indicated alternate-
ly.
50Stop lamp switchAccelerator pedal position
Ignition switch: ON
DepressedON
Ignition switch: ON
ReleasedOFF
56Pressure switchForced activation No.13 or
No.14 is being executed.Electric pump in
operationLow
Electric pump
not in operationHigh
59ABS monitorABS monitorON
ABS not in operationOFF

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-II.
Item No.Check itemChecking requirementsNormal value
10Air bleedingSupply 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.
11Oil level checkLet the directional valve operate to
left and right 20 times.To be checked by oil level in
reservoir tank.
12Electric pump operationLet the electric pump operate for 5
seconds.Operation sounds of the electric
pump are to be heard.
13Clutch 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.
14Clutch 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.
15Control OFFTurn 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-II is removed.

The clear key of MUT-II 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 itemCheck requirementNormally
1Lateral acceleration sensorIgnition switch: ON2.4 – 2.6 V
(horizontal position)
2Longitudinal acceleration
sensor ground
Lateral acceleration sensor
groundAt all times0 V
3Longitudinal acceleration
sensorIgnition switch: ON2.4 – 2.6 V
(horizontal position)
4Steer sensor (ST-2)Engine: Idle speed
Turn steering wheel slowly.0 V ↔ approx. 3 V
flashing
5Steer sensor (ST-1)Engine: Idle speed
Turn steering wheel slowly.0 V ↔ approx. 3 V
flashing
6*1FR wheel speedVehicle stationary1 V or less
Forward vehicle slowly.0 – 5 V
7*1FL wheel speedVehicle stationary1 V or less
Forward vehicle slowly.0 – 5 V
8*1RR wheel speedVehicle stationary1 V or less
Forward vehicle slowly.0 – 5 V
9*1FL wheel speedVehicle stationary1 V or less
Forward vehicle slowly.0 – 5 V
10Diagnosis selection inputWhen MUT-II is connected1 V or less
When MUT-II is disconnectedSystem voltage
11Stop lamp switchIgnition switch:
ON
Stop lamp switch: ONSystem voltage
ON
Stop lamp switch: OFF1 V or less
12*1ABS monitorWhen ABS monitor is activatedSystem voltage
When ABS monitor is deactivated1 V or less

REAR AXLE – Troubleshooting <AYC>27-29
Terminal
No.Normally Check requirement Check item
17Steer sensor (ST-N)Engine:
Idle speed
Steering wheel: Neutral position0.5 V or less
Idle speed
Steering wheel: Turned 90 from
neutral position2.5 – 3.5 V
18TPSIgnition switch:
ON
Accelerator pedal: Fully closed0.3 – 1.0 V
ON
Accelerator pedal: Fully open4.5 – 5.0 V
23Diagnosis data input/outputWhen MUT-II is connectedSerial communica-
tion with MUT-II
When MUT-II is disconnected1 V or less
24Idle position switchIgnition switch:
ON
Accelerator pedal: Fully closed2 V or less
ON
Accelerator pedal: Fully open4.5 – 5.0 V
25Accumulator pressure
switchIgnition switch:
ONAccumulator internal pressure:
Low2 V or less
Accumulator internal pressure:
HighSystem voltage
26ECU groundAt all times0 V
31AYC-ECU power supplyIgnition switch: ONSystem voltage
Ignition switch: OFF0 V
35AYC motor relayIgnition switch:
ON
When motor is energizedSystem voltage
ON
When motor is deenergized2 V or less
36AYC warning lampIgnition switch:
ON
When lamp is OFFSystem voltage
ON
When lamp is ON2 V or less
37Directional control valve
(right)
Ignition switch:
ON
Right clutch: ONSystem voltage
(right)ON
Right clutch: OFF0 V
38Proportioning valveIgnition switch:
ONAYC-ON0 V to system volt-
age
AYC-OFF0 V
39ECU backup power supplyAt all timesSystem voltage
45Directional control valve
(left)
Ignition switch:
ON
Left clutch: ONSystem voltage
(left)ON
Left clutch: OFF0 V
46ECU groundAt all times0 V
NOTE
*1: Indicates the vehicles with ABS.

REAR AXLE – Troubleshooting <AYC>27-30
LISTING OF RESISTANCE AND CONTINUITY ACROSS CONNECTOR TERMINALS ON HARNESS
SIDE

Measure the resistance and check for continuity with the ignition switch in the “OFF” position and
AYC-ECU connector disconnected.

Measure the resistance and check for continuity across terminals listed below.

Fig. below shows the arrangement of terminals.
Terminal No.Signal nameNormally
2 – body groundLongitudinal acceleration sensor ground, lateral acceleration sensor groundConducting
26 – body groundECU groundConducting
35 – body groundAYC motor relayConducting
37 – body groundDirectional control valve (right)15.4 – 16.4 Ω
38 – body groundProportioning valve3.4 – 4.0 Ω
45 – body groundDirectional control valve (left)15.4 – 16.4 Ω
46 – body groundECU groundConducting
6 – 19*2Speed sensor (front, RH)1.4 – 1.8 kΩ
7 – 20*2Speed sensor (front, LH)1.4 – 1.8 kΩ
8 – 21*2Speed sensor (rear, RH)1.4 – 1.8 kΩ
9 – 22*2Speed sensor (rear, LH)1.4 – 1.8 kΩ
NOTE
*2: Indicates the vehicles without ABS.

REAR AXLE – On-vehicle Service <Vehicles with AYC>27-31
ON-VEHICLE SERVICE
<VEHICLES WITH AYC>
REAR AXLE TOTAL BACKLASH CHECK
If the drive system roars or the vehicle vibrates, use the
following procedure to measure total backlash in the rear
axle. Based on the measurement taken, determine whether
the differential carrier assembly needs to be removed or not.
1. Place the shift lever in the neutral position and operate
the parking brake.
2. Turn the propeller shaft fully clockwise and make an
alignment mark on the companion flange dust cover and
gear carrier.
3. Turn the propeller shaft fully counterclockwise and
measure the deviation between the alignment marks.
Limit: 5 mm
4. If the backlash exceeds the limit, replace the differential
carrier assembly.
GEAR OIL LEVEL CHECK
DIFFERENTIAL
1. Remove the filler plug.
2. Check that the gear oil level is within the specified range
from the bottom end of the filler plug hole.
Standard value (A): 6 mm
3. If the gear oil level exceeds the standard value, add the
specified gear oil up to the bottom end of the filler plug
hole.
Specified gear oil:
Hypoid gear oil API classification GL-5 or higher
SAE viscosity Number 90, 80W.
NOTE
10C or more: #90, less than 10C: #80
4. Fit the filler plug and tighten it to the specified torque.
Alignment marks
Filler plug
49 Nm
Gear oil
Upper
limit
Lower
limit

REAR AXLE – On-vehicle Service <Vehicles with AYC>27-32
TORQUE TRANSFER MECHANISM
1. Remove the filler plug.
2. Check that the gear oil level is up to the bottom end
of the filler plug hole.
3. If the gear oil level is lower than the bottom end of the
filler plug hole, add the specified gear oil up to the bottom
end of the filler plug hole.
Specified gear oil:
MITSUBISHI GENUINE DIA QUEEN SUPER AYC
FLUID
4. Fit the filler plug and tighten it to the specified torque.
GEAR OIL CHANGE
DIFFERENTIAL
1. Remove the drain plug to discharge the gear oil.
2. Fit the drain plug and tighten it to the specified torque.
Tightening torque: 49 Nm
3. Remove the filler plug and add the specified gear oil
up to the bottom end of the filler plug hole.
Specified gear oil:
Hypoid gear oil API classification GL-5 or higher
SAE viscosity Number 90, 80W.
Quantity used: 0.41 ± 0.02

NOTE
10C or more: #90, less than 10C: #80
4. Fit the filler plug and tighten it to the specified torque.
Filler plug
49 Nm
Gear oil
Filler plug
49 Nm
Gear oil
Drain plug

REAR AXLE – On-vehicle Service <Vehicles with AYC>27-33
TORQUE TRANSFER MECHANISM
1. Remove the drain plug to discharge the gear oil.
2. Fit the drain plug and tighten it to the specified torque.
3. Remove the filler plug.
4. Pour the specified gear oil up to the bottom end of the
filler plug hole using an oil syringe (recommended tool)
through the gap between the body and the differential
support arm.
Specified gear oil:
MITSUBISHI GENUINE DIA QUEEN SUPER AYC
FLUID
Quantity used: 0.70
0
0.05

5. Fit the filler plug and tighten it to the specified torque.
FLUID LEVEL CHECK
1. Remove the maintenance lid located in the luggage
compartment.
2.<When MUT-II is not used>
If the vehicle has been run, leave it for 5 min. or more
in an ordinary temperature (10C to 30C) to allow the
accumulator internal pressure to drop.
NOTE
If the ambient temperature is less than 10C or less,
allow more time to leave the vehicle to stand idle.
<When MUT-II is used>
Connect the MUT-II to the 16-pin diagnosis connector.
Turn on the ignition switch. Operate the MUT-II (Item
No.11) to activate the hydraulic unit forcibly for removing
the pressure from inside the accumulator.
Caution
Before connecting or disconnecting the MUT-II,
always turn off the ignition switch.
NOTE
(1) The forced activation (oil level check mode) will be
automatically canceled as soon as the directional
valve in the hydraulic unit is activated to the left and
right 20 times.
It can also be canceled forcibly by operating the clear
key on the MUT-II.
(2) While this function is being disabled by the fail-safe
function, the forced activation of the hydraulic unit
can not be executed.
3. Check that the fluid level in the oil reservoir is in the
range between MAX and MIN.
4. If the fluid level is lower than MIN, add the specified
fluid.
Specified fluid: Dia Queen ATF SP II or equivalent
5. Reinstall the maintenance lid.
Gear oil
Drain plug
49 Nm
Oil syringe
(Recommended tool)
Filler plug
49 Nm

REAR AXLE – On-vehicle Service <Vehicles with AYC>REAR AXLE – On-vehicle Service <Vehicles with AYC>27-34
BLEEDING
1. Lift up the vehicle.
2. Connect the MUT-II to the 16-pin diagnosis connector.
Caution
Before connecting or disconnecting the MUT-II,
always turn off the ignition switch.
3. Turn on the ignition switch.
4. Operate the MUT-II (Item No.10) to activate the hydraulic
unit forcibly.
NOTE
(1) The forced activation (air bleeding mode) will be
automatically canceled after 5 minutes operation. It
can also be canceled forcibly by operating the clear
key on the MUT-II.
(2) While this function is being disabled by the fail-safe
function, the forced activation of the hydraulic unit
can not be executed.
5. Remove the cap of the left bleeder screw on the torque
transfer differential and connect a vinyl hose.
6. Gradually turn the steering wheel clockwise from the
straight-ahead position. At this time, loosen the left bleeder
screw and check that fluid is discharged with air.
7. After air has been completely discharged, tighten the
bleeder screw.
Caution
While the system is being bled of air, add fluid as
necessary to ensure that it is left in the oil reservoir
during the entire procedure.
8. Repeat steps (6) and (7) two to three times until no air
bubbles are recognized in the fluid that comes out. Then,
tighten the bleeder screw to the specified torque.
Tightening torque: 9 Nm
9. Perform steps (5) through (8) for the right bleeder screw.
Note, however, that the steering wheel should be turned
counterclockwise.
10. After the system has been completely bled of air, check
for the fluid level. (Refer to P.27-33.)
Caution
If the system is not completely bled of air, the hydraulic
unit could generate noise, degrading pump durability.
AYC OPERATION CHECK
1. Lift up the vehicle.
2. Connect the MUT-II to the 16-pin diagnosis connector.
Caution
Before connecting or disconnecting the MUT-II, always
turn off the ignition switch.
3. Start the engine.
4. Operate the MUT-II with the transmission in 2nd or a
higher gear and check to ensure that the vehicle speed
is higher than 10 km/h using the Data List (Item 10).
Bleeder
screws Vinyl hose