ABS MITSUBISHI LANCER EVOLUTION VI 1999 User Guide

REAR AXLE – Troubleshooting <AYC>27-14
Code No. 65: ABS monitor systemProbable cause
This code is output when ABS is considered to remain activated (motor relay remains
ON) for a continuous 1-min.-or-more period.
It is output also when there is an open-circuit in the harness between ABS motor
relay and AYC-ECU.
Defective harness or connector

Defective AYC-ECU
OK
Replace AYC-ECU.
NG
Check the harness between ABS
motor relay and AYC-ECU.NG
Repair
OK
Check the trouble symptom.
Is the ABS diagnosis code output?YESRefer to Group 35B – Troubleshooting
NO
Check the following connector:
B-95NG
Repair
Code No. 71: Proportioning valve systemProbable cause
This code is output when the proportioning valve control circuit is open- or short-circuited.
Defective proportioning valve

Defective harness or connector

Defective AYC-ECU
OK
Check and repair the harness between
proportioning valve and body ground.
OK
Check the trouble symptom.
OK
Measure at F-27 proportioning valve
connector.

Disconnect the connector and
measure at the harness side.

Continuity across 2 and body
ground
OK:ConductingNGCheck the following connectors:
F-27, F-30NG
Repair
Measure at F-27 proportioning valve
connector.

Disconnect the connector and
measure at the proportioning valve.

Resistance across 2 – 3
OK:4.7 Ω or lessNGReplace the hydraulic unit.
OK
Replace AYC-ECU.
NG
Check the harness between propor-
tioning valve and AYC-ECU.NG
Repair
OK
Check the trouble symptom.
OK
Check the following connectors:
B-96, B-94, D-06, F-30, F-27NG
Repair

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>27-28
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>27-37
WHEEL SPEED SENSOR OUTPUT VOLTAGE
MEASUREMENT <VEHICLES WITHOUT ABS>
1. Lift up the vehicle and release the parking brake.
2. Disconnect the AYC-ECU harness connector and take
measurements on the harness side connector.
Caution
Insert the probe from the harness side with the double
lock of the connector unlocked. Inserting it to the
terminal side could result in poor contact.
3. Turn the wheel to be tested at about 1/2 to one
revolution/sec. and check for the output voltage using
a circuit tester (AC mV range) or oscilloscope.
Terminal nos.
Front LHFront RHRear LHRear RH
7698
20192221
Output voltage:
When circuit tester is used: 70 mV or more
When oscilloscope is used: 200 mVp-p or more
(4) If the output voltage is lower than the above value, it
is probably attributable to the following faults. Check or
replace the wheel speed sensor as necessary.

Excessive clearance between the pole piece and rotor
of the wheel speed sensor

Defective wheel speed sensor
Waveform Check Using Oscilloscope
Check the harness and connector of the wheel speed sensor
for connection. Then, use an oscilloscope to check for output
voltage waveform of each sensor as follows.
Start the engine and monitor the sensor by turning the wheel;
for a driving wheel, let it turn by shifting into the 1st gear
and for a driven wheel turn it manually at a constant speed.
NOTE
(1) Waveform may be observed by actually running the
vehicle.
(2) The output voltage is low when the wheel speed remains
low and builds up as the wheel speed increases.
AYC-ECU connector harness side
When turned manually
At idle (5 to 6 km/h)
1st gear

REAR AXLE – On-vehicle Service <Vehicles with AYC>27-38
Waveform Observation Points
SymptomProbable causeAction
Waveform amplitude is too small, or no
waveform.Defective wheel speed sensorReplace sensor.
Waveform amplitude varies greatly. (No
problem ifthe smallest amplitude is 100
Excessive axle hub lateral and radial runoutReplace hub.
problem if the smallest amplitude is 100
mV or more)Poor AYC-ECU groundingRepair.
Noise on waveform or disturbed
waveform
Open-circuited sensorReplace sensor.
waveform
Open-circuited harnessRepair harness.
Improperly mounted wheel speed sensorCorrect sensor installation.
Missing or collapsed ABS rotor toothReplace ABS rotor.
Caution
Since the wheel speed sensor cable follows the movement of the front or rear suspension, it
may be open-circuited only when the vehicle is run on rough roads and not on ordinary road.
The wheel speed sensor output voltage waveform should therefore be checked also by rocking
the sensor harness so that driving on rough roads may be simulated.
ACTION WHEN BATTERY RUNS OUT
When the engine is started using a booster cable where the
battery has completely run down and you attempt to start
the vehicle without waiting for the battery to recover a certain
charge, the engine can misfire and you just cannot start to
move it. In such cases, charge the battery sufficiently; or,
remove the AYC fusible link from the engine compartment
relay box to make AYC inactive before attempting to start
the vehicle. When the fusible link is removed, the AYC warning
lamp lights up. After the battery has been recharged, fit the
fusible link back again and start the engine to ensure that
the AYC warning lamp is off.AYC fusible link

– Heater Unit, Cooling and Blower Unit HEATER AND MANUAL
AIR CONDITIONER55-19
HEATER UNIT, COOLING AND BLOWER UNIT
<VEHICLES WITH AIR CONDITIONER>
REMOVAL AND INSTALLATION
Pre-removal and Post-installation Operation

Engine Coolant Draining and Refilling

Discharging and Charging of Refrigerant
(Refer to P.55-6.)

Air Cleaner Cover and Hose Removal and
Installation

Floor Console and Instrument Panel Removal and
Installation

Rear Seat Heater Duct Removal and Installation
<Vehicles for cold regions> (Refer to P.55-31.)
1
34
5 6
2 7
8 9
10 1112
Piping connection
O-ring
A/C Compressor oil: SUN PAG 56
Removal steps
1. Center reinforcement RH
2. Heater control assembly
3. Center reinforcement LH
4. Center ventilation duct
5. Foot distribution duct
6. Drain hose
A7. Connection between cooling unit
and refrigerant line8. Cooling and blower unit
9. Heater hose
10. Heater unit
11. Heater core support
12. Heater core
REMOVAL SERVICE POINT
AREMOVAL OF REFRIGERANT LINE FROM
COOLING UNIT
Plug the open end of the removed hose and the opening
in the cooling unit to prevent entry of dust and foreign
substances.
Caution
Compressor oil and the receiver are highly
moisture-absorptive.
Do not use plugs allowing ventilation.

– Blower Motor Assembly, Resistor and Evaporator HEATER AND MANUAL
AIR CONDITIONER55-20
BLOWER MOTOR ASSEMBLY, RESISTOR AND EVAPORATOR
REMOVAL AND INSTALLATION
4
6 2
1 5
3
7
Piping connection
O-ring
A/C Compressor oil: SUN PAG 56
Blower motor assembly removal
steps
1. Under cover
<Vehicles for cold regions>
2. Blower motor assembly
Resistor removal steps
1. Under cover
<Vehicles for cold regions>

Glove box, glove box frame
3. ResistorEvaporator removal steps
<Vehicles with A/C>

Discharging and Charging of
refrigerant (Refer to P.55-6.)

Glove box, glove box frame
4. Drain hose
A5. Connection between evaporator
and refrigerant line
B6. Case cover
B7. Evaporator
REMOVAL SERVICE POINT
AREMOVAL OF REFRIGERANT LINE FROM
EVAPORATOR
Plug the open end of the removed hose and the opening
in the evaporator to prevent entry of dust and foreign
substances.
Caution
Compressor oil and the receiver are highly
moisture-absorptive.
Do not use plugs allowing ventilation.

– Compressor and Tension Pulley HEATER AND MANUAL
AIR CONDITIONER55-24
REMOVAL SERVICE POINTS
ADRIVE BELT REMOVAL
1. Align the hole in the auto-tensioner bracket with that in
the arm and insert a screwdriver into the holes.
2. Remove the drive belt.
BSUCTION HOSE, DISCHARGE HOSE
DISCONNECTION
Plug the disconnected hose and the compressor nipple not
to let foreign matter get into them.
Caution
Seal the hoses completely, otherwise the compressor
oil and receiver will absorb water vapour easily.
CCOMPRESSOR REMOVAL
When doing this work, be careful not to spill the compressor
oil.
Auto-tensioner
Hole in
arm
Hole in
bracket
Screwdriver (+)