1999 MITSUBISHI LANCER EVOLUTION VI steering

MPI – Troubleshooting13-50
INSPECTION PROCEDURE 42
MUT-II: Engine stalling inspection when the engine is warmed up and idling.
OK
MUT-II Data list
26 Idle position switch (Refer to P.13-58.)NGCheck the idle position switch system.
(Refer to P.13-38, INSPECTION PROCEDURE 26.)
OK
MUT-II Data list
13 Intake air temperature sensor (Refer to P.13-56.)NGCheck the intake air temperature sensor system. (Refer to P.13-9,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 13.)
OK
MUT-II Data list
25 Barometric pressure sensor (Refer to P.13-58.)NGCheck the barometric pressure sensor system. (Refer to P.13-14,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 25.)
OK
MUT-II Data list
21 Engine coolant temperature sensor (Refer to P.13-57.)NGCheck the engine coolant temperature sensor system.
(Refer to P.13-10, INSPECTION PROCEDURE FOR DIAGNOSIS
CODE 21.)
OK
MUT-II Data list
11 Oxygen sensor
OK:600–1,000 mV during sudden racingNGCheck the oxygen sensor system. (Refer to P.13-42, INSPECTION
PROCEDURE 31.)
OK
MUT-II Data list
11 Oxygen sensor
OK:Changes between 0–400 mV and 600–1,000 mV during
idlingNGCheck the fuel pressure. (Refer to P.13-30.)*
OK
MUT-II Data list
27 Power steering fluid pressure switch (Refer to P.13-58.)NGCheck the power steering fluid pressure switch system.
(Refer to P.13-39, INSPECTION PROCEDURE 28.)
OK
MUT-II Data list
28 A/C switch (Refer to P.13-58.)NGCheck the A/C switch and A/C relay system.
(Refer to P.13-39, INSPECTION PROCEDURE 29.)
OK
MUT-II Data list
45 ISC servo position (Refer to P.13-60.)NGAdjust the basic idle speed. (Refer to P.13-30.)*
1. Inspect the intake of air into the air intake system

Broken intake manifold gasket

Broken vacuum hose

PCV valve does not operate.

Broken air intake hose
2. Check the injector for clog.
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).

MPI – Troubleshooting13-58
Item
No.Reference
page Inspection
procedure
No. Normal condition Inspection contents Inspection
item
22Crank angle
sensor
Engine: Cranking

Tachometer:
ConnectedCompare the engine
speed readings on
the tachometer and
the MUT-II.Accord––

Engine: Idling

Idle position
switch: ONWhen engine
coolant temperature
is –20C1,300 – 1,500 rpm
When engine
coolant temperature
is 0C1,300 – 1,500 rpm
When engine
coolant temperature
is 20C1,300 – 1,500 rpm
When engine
coolant temperature
is 40C1,150 – 1,350 rpm
When engine
coolant temperature
is 80C750 – 950 rpm
25Barometric
pressure
Ignition switch: ONAt altitude of 0 m101 kPaCode No.
25
13-14
pressure
sensor
At altitude of 600 m95 kPa
25
At altitude of 1,200 m88 kPa
At altitude of 1,800 m81 kPa
26Idle position
switchIgnition switch: ON
Check by operating
accelerator pedal
Throttle valve:
Set to idle positionONProcedure
No. 2613-38
accelerator pedal
repeatedly.)Throttle valve:
Slightly openOFF*
27Power
steering fluid
pressure
Engine: IdlingSteering wheel
stationaryOFFProcedure
No. 2813-39
pressure
switchSteering wheel
turningON
28A/C switchEngine: Idling
(when A/C switch isA/C switch: OFFOFFProcedure
No. 2913-39
(Ctc
ON, A/C compressor
should be operating.)A/C switch: ONON
NOTE
*: The idle position switch normally turns off when the voltage of the throttle position sensor is 50 –
100 mV higher than the voltage at the idle position. If the throttle position switch turns back on
after the throttle valve has opened, the idle position switch and the throttle position sensor need
to be adjusted.

MPI – Troubleshooting13-64
Terminal
No.Normal condition Check condition (Engine condition) Check item
20Radiator fan motor
relay (HI)

Radiator fan not operating (coolant temperature:
95C or below)System voltage
Radiator fan at high speed (coolant temperature:
105C or above)0 – 3 V
21Fan motor relay (LOW)
Fan not operating (coolant temperature: 95C or
below)System voltage
Fan at low speed (coolant temperature: 95 – 100C)0 – 3 V
21Radiator fan motor
relay (LOW)

Radiator fan not operating (coolant temperature:
95C or below)System voltage
Radiator fan at low speed (coolant temperature: 95
– 105C)0 – 3 V
22A/C relay
Engine: Idling

A/C switch: OFF to ON (Compressor is being
driven.)System voltage, or 6
V or more instanta-
neously to 0 – 3 V
32A/C condenser fan
motor relay (HI)

A/C condenser fan not operating (A/C switch: ON,
coolant temperature: 105C or below)System voltage
A/C condenser fan at high speed (A/C switch: ON,
coolant temperature: 105C or above)0 – 3 V
33Alternator G terminal
Engine: Warm, idle (radiator fan: OFF)

Headlamp: OFF to ON

Brake lamp: OFF to ON

Rear defogger switch: OFF to ONVoltage rises by 0.2 –
3.5 V.
34A/C condenser fan
motor relay (LOW)

A/C condenser fan not operating (A/C switch: OFF,
coolant temperature: 105C or below)System voltage
A/C condenser fan at low speed (A/C switch: OFF,
coolant temperature: 105C or above)0 – 3 V
36Engine warning lampIgnition switch: OFF → ON0 – 3 V → System
voltage (After several
seconds have
elapsed)
37Power steering fluid
pressure switchEngine: Idling after
warming upWhen steering wheel is
stationarySystem voltage
When steering wheel is
turned0 – 3 V
38Control relayIgnition switch: OFFSystem voltage
Ignition switch: ON0 – 3 V
39Fuel pump relay No.2While engine is idling, suddenly depress the
accelerator pedal.Momentarily rises
slightly from 0 to 3 V.
40Exhaust temperature
warning lampIgnition switch: OFF to ON0 – 3 V to system
voltage (After several
seconds have
elapsed)

REAR AXLE – Special Tools / Troubleshooting 27-4
MB990925
Brass bar
Bar (one-touch type)Toolbox
Installer adapter
Tool number (MB990925)O.D. mmTool number (MB990925)O.D. mm
AMB99092639.0AMB99093363.5
MB99092745.0MB99093467.5
MB99092849.5MB99093571.5
MB99092951.0MB99093675.5
MB99093054.0MB99093779.0
MB99093157.0BMB990938–
MB99093261.0CMB990939–
TROUBLESHOOTING
BASIC TROUBLESHOOTING CONDITIONS
Refer to Group 00 – How to Use Troubleshooting / Inspection Service Points.
NOTE
Before starting the troubleshooting procedure, make sure that the following items have been checked
okay.

The correct steering wheel has been properly installed in the neutral position of the steering column
shaft.

Tire and wheel sizes are correct with correct specifications. Inflation pressure, balance, and wear
conditions are okay.

Wheel alignment is correct.

The engine, suspension, and other parts have not been remodeled so as to affect the AYC system.
DIAGNOSIS FUNCTION
READING THE DIAGNOSIS CODE
Read the diagnosis code using an MUT-II tester or the AYC warning lamp.
(Refer to Group 00 – How to Use Troubleshooting / Inspection Service Points.)
ERASING THE DIAGNOSIS CODE
Refer to Group 00 – How to Use Troubleshooting / Inspection Service Points.

REAR AXLE – Troubleshooting 27-8
Code No. 25: Wrong-diameter tireProbable cause
This code is output if the speed of any one of the four wheels exceeds a specified
level with respect to the average of the four wheel speed sensor outputs when the
steering wheel is in the straight-ahead position and the vehicle speed exceeds 20
km/h. At this time, the warning lamp does not light up.
Defective harness or connector

Defective AYC-ECU

Defective ABS-ECU

OK
Replace ABS-ECU.
NG
Check harness between AYC-ECU
and ABS-ECU.NG
Repair
NG
Replace AYC-ECU.
OK
Check the trouble symptom.
NG
Check the following connectors:
B-24, B-95NG
Repair
OK
Check the trouble symptom.
NO
Measure at B-95 AYC-ECU connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Turn tire at 1/2 to 1 revolution/sec.

Voltage across 6/7/8/9 and body
ground.
OK:42 mV or more (when mea-
sured with a circuit tester)
120 mV-P or more (when
measured with an oscillo-
scope)OKCheck the following connector:
B-95
YES
Is ABS diagnosis code No. 15 output?YESGroup 35* – Refer to Troubleshooting
Are correct tires mounted on all four
wheels?NO
Repair
NG
Repair

NO
Repair
NOCheck and repair the harness between
wheel speed sensor and AYC-ECU.
OK
Check the trouble symptom.
OK
Check the following connectors:
B-95, B-52, B-17, A-26, A-50, D-04,
D-14, D-19NG
Repair
OK
Check wheel bearing.NG
Replace
NG
Replace AYC-ECU.
OK
Check the trouble symptom.
OK
Check the following connector:
B-95NG
Repair
OK
Check wheel speed sensor output volt-
age. (Refer to p. 27-37.)NGCheck wheel speed sensor and ABS
rotor. (Refer to Group 35B.)
YES
Check Wheel speed sensor for instal-
lation.NG
Repair
Are correct tires mounted on all four
wheels?
NG
Replace

REAR AXLE – Troubleshooting 27-10
Code No. 31: Steer sensor (ST-1, ST-2, ST-N) systemProbable cause
This code is output when any of the steer sensors ST-1, ST-2, and ST-N is open-circuited
or the steer sensor ground wire is open-circuited.
Defective steer sensor

Defective harness or connector

Defective AYC-ECU
OK
Replace the steer sensor.
NG
Check the harness between steer sen-
sor and AYC-ECU.NG
Repair
NG
Check and repair the harness between
speed sensor and AYC-ECU.
OK
Check the trouble symptom.
OK
Check the trouble symptom.
OK
Check the following connectors:
B-95, B-65, B-98NG
Repair
NG: Voltage remains
at 4 V or more.
Measure at B-98 steer sensor connec-
tor.

Disconnect the connector and
measure at the harness side.

Continuity across 3 and body
ground
OK:ConductingNGCheck the following connectors:
B-98, B-50NG
Repair
NG
Replace AYC-ECU.
OK
Check the trouble symptom.
Measure at B-95 AYC-ECU connector.

Connector connected.

Ignition switch: ON

Voltage across 4/5/17 and body ground.
OK:The voltage alternates between about
3 V and about 0.5 V when the steering
wheel is turned.OKCheck the following connector:
B-95NG
Repair
NG: Voltage alternates
between 4 V or
more and 0.5 V.NG: Voltage
remains
at 0 V.
Code No. 32: Steer sensor (ST-N) systemProbable cause
This code is output when the steering wheel is considered to be turned 40 or more
as determined with ST-1 and ST-2 with ST-N ON (LOW voltage).
Defective steer sensor

Defective harness or connector

Defective AYC-ECU
OK
Replace the steer sensor.
NG
Check the harness between steer sen-
sor and AYC-ECU.NG
Repair
OK
Replace AYC-ECU.
NG
Replace AYC-ECU.
OK
Check the trouble symptom.
OK
Check the trouble symptom.
NG
Measure at B-95 AYC-ECU connector.

Disconnect the connector and
measure at the harness side.

Ignition switch: ON

Turn steering wheel about 90 in
either direction from the straight-
ahead position.

Voltage across 17 and body
ground.
OK:No continuityNGCheck the following connectors:
B-95, B-65, B-98NG
Repair
Measure at B-95 AYC-ECU connector.

Connector connected.

Ignition switch: ON

Turn steering wheel about 90 in
either direction from the straight-
ahead position.

Voltage across 17 and body
ground.
OK:The voltage increases from
about 0.5 V or less to about
3 V.OKCheck the following connector:
B-95NG
Repair

REAR AXLE – Troubleshooting 27-11
Code No. 33: Steer sensor (ST-N) systemProbable cause
This code is output when the steering wheel is turned 400 or more in the same
direction with ST-N OFF (HIGH voltage).
Defective steer sensor

Defective harness or connector

Defective AYC-ECU
NG
Replace AYC-ECU.
Check the trouble symptom.
OK
Replace the steer sensor.
NG
Check the harness between steer sen-
sor and AYC-ECU.NG
Repair
OK
Replace AYC-ECU.
OK
Check the trouble symptom.
Measure at B-95 AYC-ECU connector.

Connector connected.

Ignition switch: ON

Turn steering wheel about 90 in
either direction from the straight-
ahead position.

Voltage across 17 and body
ground.
OK:The voltage increases from
about 0.5 V or less to about
3 V.NGCheck the following connectors:
B-95, B-65, B-98NG
Repair
Code No. 34: Steer sensor (ST-1, ST-2) systemProbable cause
This code is output if a turning condition is detected for a cumulative period of time
of 15 min. or more, during which there is no change in the steer sensor (ST-1, ST-2)
signals with the wheel speed 15 km/h or more.
Defective steer sensor

Defective harness or connector

Defective AYC-ECU
NG
Replace AYC-ECU.
Check the trouble symptom.
OK
Replace the steer sensor.
NG
Check the harness between steer sen-
sor and AYC-ECU.NG
Repair
OK
Replace AYC-ECU.
OK
Check the trouble symptom.
Measure at B-95 AYC-ECU connector.

Connector connected.

Ignition switch: ON

Voltage across 4/5 and body
ground
OK:The voltage alternates
between about 0.5 V and
about 3 V as the steering
wheel is turned.NGCheck the following connectors:
B-95, B-65, B-98NG
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