ECU MITSUBISHI LANCER EVOLUTION IV 1998 Owner's Manual

MPI – Troubleshooting13-18
5. SERVICE DATA LIST

Item
No.Inspection
itemInspection contentsNormal condition
11Oxygen
sensorEngine: After having been warmed
up
Air/fuel mixture is made leaner when
When at 4,000 r/min, engine is
suddenly decelerated200 mV or less
Air/fuel mixture is made leaner when
decelerating, and is made richer
when racing.
When engine is suddenly
raced600 – 1,000 mV
Engine: After having been warmed
up
The ox
ygen sensor signal is used to
Engine is idling400 mV or less
(Chan
ges)The oxygen sensor signal is used to
check the air/fuel mixture ratio, and
control condition is also checked by
the ECU.2,500 r/min
(Changes)
600 – 1,000 mV
12Air flow
sensor*
Engine coolant temperature:
8095C
Engine is idling17 – 43 Hz
sensor*80 – 95C
Lamps, electric cooling fan and
all accessories: OFF
2,500 r/min46 – 86 Hz
all accessories: OFF
Transmission: NeutralEngine is racedFrequency increases
in response to racing
13Intake air
temperature
sensor
Ignition switch: ON or with engine
runningWhen intake air temperature
is –20C–20C
sensorWhen intake air temperature
is 0C0C
When intake air temperature
is 20C20C
When intake air temperature
is 40C40C
When intake air temperature
is 80C80C
14Throttle
position
Ignition switch: ONSet to idle position300 – 1,000 mV
position
sensor
Gradually openIncreases in proportion
to throttle opening
angle
Open fully4,500 – 5,500 mV
16Power
supply
voltageIgnition switch: ONSystem voltage
18Cranking
signal Ignition switch: ONEngine: StoppedOFF
g
(ignition
switch-ST)Engine: CrankingON
NOTE
*: When the car is new (distance it travelled is less than 500 km), output frequency of the air flow sensor may
become about 10% higher.

MPI – Troubleshooting13-22
6. ENGINE-ECU INSPECTION
6-1 TERMINAL VOLTAGES
Engine ECU connector
Terminal
No.Check itemCheck condition (Engine condition)Normal condition
1No.1 injectorWhile engine is idling after having been warmed up,
suddenly depress the accelerator pedal
Momentarily drops
slightlyfrom 1114V
14No.2 injector
suddenly depress the accelerator pedal.slightly from 11 – 14 V.
2No.3 injector
15No.4 injector
3Fuel pressure control
valve
Ignition switch: ONBattery voltage
valve
Engine: Cranking to idling (within about two minutes)0 – 3 V to battery
voltage
4Stepper motor coil (A1)Engine: Immediately after engine has been started
f
or warming up
Changes repeatedly
f
rom battery voltage to
17Stepper motor coil (A2)
for warming upfrom battery voltage to
0 – 6 V and from 0 – 6
V to battery voltage5Stepper motor coil (B1)V to battery voltage.
18Stepper motor coil (B2)
6Secondary air control
solenoid valveIgnition switch: ONBattery voltage
8Fuel pump relayIgnition switch: ONBattery voltage
Engine: Idling0 – 3 V
10Power transistor unit
(A)Engine speed: 3,000 r/min0.3 – 3.0 V
23Power transistor unit
(B)
11Wastegate solenoid
valve
Ignition switch: ONBattery voltage
valve
Engine: At idle after having been warmed up (when
premium gasoline is used)0 – 3 V
12Power supplyIgnition switch: ONBattery voltage
25
19Air flow sensor reset
signal
Engine: Idling0 – 1 V
signal
Engine speed: 3,000 r/min6 – 9 V
20Fan motor relay (HI)Fan not operating (coolant temperature: 90C or
below)Battery voltage
Fan at high speed (coolant temperature: 105C or
above)0 – 3 V

MPI – Troubleshooting13-25
6-2 RESISTANCE AND CONTINUITY BETWEEN HARNESS SIDE CONNECTORS AND
TERMINALS
Engine-ECU Harness Side Connector Terminal Arrangement
Terminal No.Inspection itemNormal condition (Check condition)
1 – 12No.1 injector2 – 3 Ω (At 20C)
14 – 12No.2 injector
2 – 12No.3 injector
15 – 12No.4 injector
3 – 12Fuel pressure control valve28 – 36 Ω (At 20C)
4 – 12Stepper motor coil (A1)28 – 33 Ω (At 20C)
17 – 12Stepper motor coil (A2)
5 – 12Stepper motor coil (B1)
18 – 12Stepper motor coil (B2)
6 – 12Secondary air control solenoid valve28 – 36 Ω (At 20C)
11 – 12Wastegate solenoid valve62 – 74 Ω (At 20C)
13 – Body earthEngine-ECU earthContinuity established (0 Ω)
26 – Body earth
60 – 12Oxygen sensor heater (EVOLUTION-V
only)11 – 18 Ω (at 20C)
72 – 92Intake air temperature sensor5.3 – 6.7 kΩ (When intake air temperature is 0C)
2.3 – 3.0 kΩ (When intake air temperature is 20C)
1.0 – 1.5 kΩ (When intake air temperature is 40C)
0.30 – 0.42 kΩ (When intake air temperature is 80C)
74 – 77High temperature sensor3 Ω or less
83 – 92Engine coolant temperature sensor5.1 – 6.5 kΩ (When coolant temperature is 0C)
2.1 – 2.7 kΩ (When coolant temperature is 20C)
0.9 – 1.3 kΩ (When coolant temperature is 40C)
0.26 – 0.36 kΩ (When coolant temperature is 80C)
87 – 92Idle position switchContinuity established (when throttle valve is at idle
position)
No continuity (when throttle valve is slightly open)
91 – Body earth–Continuity established

MPI – Troubleshooting13-26
7. INSPECTION PROCEDURE USING
OSCILLOSCOPE
7-1 AIR FLOW SENSOR (AFS)
Observing waveforms displayed on the oscilloscope allows
you to visually identify possible unusual disturbances in
waveform that could temporarily occur in the air flow sensor
output.

(1) Disconnect the air flow sensor connector and connect
the special tool (Test Harness: MB991709) to it. (Ensure
that all terminals are connected.)
(2) Connect the oscilloscope probe to terminal no. 3 of air
flow sensor connector.
NOTE
If the engine ECU connector is used, connect the
oscilloscope probe to terminal no. 90.
(3) Perform the same steps from here on as with the 4G9
engine.
7-2 CAMSHAFT POSITION SENSOR AND CRANK
ANGLE SENSOR
Perform the same steps as with the conventional 4G9 engine
for the inspection.
7-3 INJECTOR
Observing waveforms displayed on the oscilloscope allows
you to visually check the conditions of injector drive signals
actually output from the engine ECU.
Injector Control Signal (Oscilloscope 1)

(1) Disconnect the injector connector and connect the special
tool (Test Harness: MB991348) to the circuit. (Ensure
that the terminals on both the power supply and engine
ECU sides are connected.)
(2) Connect the oscilloscope probe to terminal no. 2 of injector
connector.
NOTE
If the engine ECU connector is used for the measurement,
take measurements at each of the following terminals.
Connect the oscilloscope probe to terminal no. 1 when
the waveform is observed with no. 1 cylinder, to terminal
no. 14 when the waveform is observed with no. 2 cylinder,
to terminal no. 2 when the waveform is observed with
no. 3 cylinder, and to terminal no. 15 when the waveform
is observed with no. 4 cylinder.
Oscilloscope
Oscilloscope

MPI – Troubleshooting13-27

Observation conditions
Probe selector switch× 10
AC-GND-DCDC
VOLTS/DIV.1 V
TIME/DIV.0.5 ms
Misc.–
Engine speedIdle

The power supply voltage is being normally applied and, when a signal is received from the engine
ECU, the voltage drops to around 0 V for the period of time equivalent to its drive signal.
When the signal from the engine ECU turns OFF, the counter emf of the coil causes a voltage peak
to develop, thus resuming the power supply voltage.
Injector drive time:
The fuel injection time as determined by the engine ECU according to the output values of sensors
including AFS. Injector drive time = effective injection time + invalid injection time (Invalid injection
time: corrects operation time lag caused by a power supply voltage drop)
Solenoid coil counter emf:
When the signal from the engine ECU turns OFF, counter emf occurs in the injector coil (approx.
65 to 75 V).
Power supply voltage:
The power supply voltage is being applied in the absence of a signal from the engine ECU. If this
voltage is low, it extends the invalid injection time and, thus, the drive time.

Point A: Strength of solenoid coil counter emf
Solenoid coil counter emf is low or zero.Injector solenoid shorting
Point B: Injector drive time
When the engine is suddenly raced, the drive time temporarily
extends by a wide margin and soon returns to the normal
drive time corresponding to the engine speed.
Point A
Point B
Injector
drive timeSolenoid counter emf
(approx. 7 × 10 V)
Power supply voltage
At idle
During racing

MPI – On-vehicle Service13-31
5. MPI SYSTEM COMPONENTS LAYOUT
NameSymbolNameSymbol
A/C switchQExhaust temperature warning lampS
A/C relayHFuel pressure control valveA
Air flow sensor (with a built-in intake air temperaturesensor and barometric pressure sensor)FIgnition coil and power transistor unitLsensor and barometric pressure sensor)InjectorB
Camshaft position sensorMISC servoD
Control relay and fuel pump relayPOxygen sensorK
Coolant temperature sensorEPower steering fluid pressure switchI
Crank angle sensorJSecondary air control solenoid valveN
Detonation sensorCThrottle position sensor (with a built-in idle switch)D
Diagnosis connectorR
Engine ECUOVehicle speed sensorT
Engine warning lampSWastegate solenoid valveG

INTAKE AND EXHAUST – On-vehicle Service15-5
6. SECONDARY AIR CONTROL SYSTEM
CHECK
(1) Start the engine and let it run at idle speed.
(2) Short-circuit the no. 6 terminal of the engine ECU
connector using a jumper wire and check at this time
that the secondary air valve lifts.
At this time, the engine ECU connector should be
connected.
7. SECONDARY AIR CONTROL SOLENOID
VALVE CHECK
7-1 OPERATION CHECK
(1) Disconnect the vacuum hose (white stripe, yellow stripe)
from the solenoid valve.
(2) Disconnect the harness connector.
(3) Connect a hand vacuum pump to nipple A of the solenoid
valve.
(4) Using jumper wires, connect the solenoid valve terminal
to battery terminals.
(5) Disconnecting and reconnecting the jumper wire on the
(–) terminal side, apply vacuum to check for airtightness.
Jumper wireNipple B conditionNormally
ConnectedOpenVacuum leaks.
PluggedVacuum retained.
DisconnectedOpenVacuum leaks.
7-2 COIL RESISTANCE CHECK
Measure the resistance across solenoid valve terminals.
Standard value: 28 – 36 Ω (at 20
C)
Secondary air control
solenoid valve
Battery

MANUAL TRANSMISSION – Transmission Control22A-4
TRANSMISSION CONTROL
REMOVAL AND INSTALLATION
Pre-removal and Post-installation Operation

Air Cleaner Assembly Removal and InstallationCaution: SRS
Be careful not to subject the SRS-ECU to any shocks
during removal and installation of the shift cable
and select cable assembly.
456
7 8
9
10
11
12
13 141
2
3 8
Unit: Nm {kgfm}
12 {1.2}
12 {1.2}
Shift cable and select cable
assembly removal steps
B1. Shift knob
B2. Spring washer
B3. Nut

Front floor console
(Refer to GROUP 52.)
4. Snap pin
5. Select cable connection
(Shift lever side)
6. Clip
7. Shift cable connection
(Shift lever side)
8. Snap pin
A9. Select cable connection
(Transmission side)
A10. Shift cable connection
(Transmission side)
A11. Shift cable and select cable as-
semblyShift lever assembly removal steps
B1. Shift knob
B2. Spring washer
B3. Nut

Front floor console
(Refer to GROUP 52.)
4. Snap pin
5. Select cable connection
(Shift lever side)
6. Clip
7. Shift cable connection
(Shift lever side)
12. Shift lever assembly
13. Distance piece
14. Bushing

MANUAL TRANSMISSION OVERHAUL – Input Shaft22B-22
REASSEMBLY SERVICE POINTS

AOIL SEAL INSTALLATION
Make sure that the oil seal is pressed into the position shown
in the illustration.

BBALL BEARING INSTALLATION

CSNAP RING INSTALLATION
Select and install a snap ring so that the input shaft front
bearing end play will have the standard value.
Standard value: 0 – 0.12 mm

DSYNCHRONIZER SPRING INSTALLATION
Install the synchronizer spring securely to the illustrated
position of the outer synchronizer ring.

E3RD-4TH SPEED SYNCHRONIZER HUB
INSTALLATION
Install the synchronizer hub in such a way that it will be oriented
in the direction shown.Oil seal
3.5 mm
MD998801MD998812
MD998813
MD998818
Snap ring
Synchronizer spring
Installation
direction
Identification mark

MANUAL TRANSMISSION OVERHAUL – Center Differential22B-48
(5) Install the front output shaft to the side gear and fit the
snap ring.
(6) Attach the spacer on the other side gear, then install
the side gear in the center differential case.
NOTE
If a new side gear is to be installed, select a spacer
with medium thickness (0.8 – 0.9 mm).
(7) Install the center differential flange on the case while
aligning the mating marks, then secure it temporarily with
machine screw.
(8) Measure the backlash between the side gear and the
pinion.
Standard value: 0.025 – 0.150 mm
(9) If the measurement deviates from the standard value,
correct the backlash using a spacer of different thickness
and check it again.
NOTE
The backlash must be the same on both sides.

DCENTER DIFFERENTIAL DRIVE GEAR
INSTALLATION
(1) Apply sealant to the entire threaded portion of the bolt.
Specified sealant:
THREEBOND 1303 or LOKTITE 648
(2) Tighten the bolts to the specified torque in the illustrated
sequence.
1
8
7
6
5
4
3
2
10
9