1999 MITSUBISHI LANCER EVOLUTION VI ignition

REAR AXLE – Troubleshooting 27-21
INSPECTION PROCEDURE 2
Communication between MUT-II and the AYC-ECU is not
possible.
Probable cause
The cause may be a malfunction of the AYC-ECU power supply circuit or an open
circuit in the diagnosis output circuit.
Blown fuse

Defective harness or connector

Defective AYC-ECU
NG
Check and repair the harness between
AYC-ECU and diagnosis connctor.
OK
Check the trouble symptom.
OK
Check the following symptom.
NG
Check and repair the harness between
ignition switch (IG
2) and AYC-ECU.
OK
Check the trouble symptom.
OK
Replace AYC-ECU.
Check the following connectors:
B-96, B-94, B-49, B-75, B-76NG
Repair
OK
Measure at B-96 AYC-ECU connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Voltage across 31 and body ground
OK:System voltageNG
Measure at B-22 diagnosis connector
and B-95 AYC-ECU connector.

Disconnect the connectors and
measure at the harness side.

Continuity across 1 of B-22 and
10 of B-95

Continuity across 7 of B-22 and
23 of B-95
OK:ConductingNGCheck the following connectors:
B-95, B-65, B-22NG
Repair
OK
Measure at B-95 and B-96 AYC-ECU
connectors.

Disconnect the connectors and
measure at the harness side.

Continuity across 26/46 and body
ground
OK:ConductingNGCheck the following connectors:
B-95, B-96NG
Replace
Check and repair the harness between
AYC-ECU and earth.
NG

REAR AXLE – Troubleshooting 27-22
INSPECTION PROCEDURE 3
AYC warning lamp does not light up when the ignition key
is turned to “ON” (engine stationary).
Probable cause
The lamp power supply circuit is probably open-circuited, lamp bulb is out, or the
circuit between AYC warning lamp and AYC-ECU or AYC-ECU itself is defective.
Blown fuse

AYC warning lamp out

Defective harness or connector

Defective AYC-ECU
NG
Check and repair the harness between
ignition switch (IG
2) and AYC warning
lamp.
OK
Check the trouble symptom.
OK
Replace combination meter.
NG
Check the harness between AYC
warning lamp and AYC-ECU.NG
Repair
OK
Check the trouble symptom.OK
Replace AYC-ECU.
OK
Check the following connectors:
B-96, B-94, B-08NG
Repair
OK
Measure at B-96 AYC-ECU connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Warning lamp when 36 is grounded
to body
OK:Lit upNGCheck the lamp bulb.NG
Replace
Measure at B-08 combination meter
connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Voltage across 48 and body ground
OK:Symptom voltageNGCheck the following connectors:
B-08, B-74, B-76NG
Repair

REAR AXLE – Troubleshooting 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 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 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 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 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 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.
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.

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