1999 MITSUBISHI LANCER EVOLUTION VI air condition

MPI – Troubleshooting13-15
Code No. 31 Detonation sensor systemProbable cause
Range of Check

Ignition switch: ON

Excluding 60 seconds after the ignition switch is turned to ON or immediately
after the engine starts.

Engine speed is approx. 5,000 r/min or more

Set conditions

The change in the detonation sensor output voltage (detonation sensor peak voltage
at each 1/2 revolution of the crankshaft) is less than 0.06 V for 200 times in
succession.
Malfunction of the detonation sensor

Improper connector contact, open or short-circuited
harness wire of the detonation sensor circuit

Malfunction of the engine-ECU
Measure at the detonation sensor con-
nector A-96.

Disconnect the connector and
measure at the harness side.

Continuity between 2 and earth
OK:ContinuityOKCheck the following connector:
B-62NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between the
engine-ECU and the detonation sensor
connector.OKReplace the detonation sensor.
Check trouble symptom.
NG
Replace the engine-ECU.
NG
Repair
NG
Check the harness wire between the
detonation sensor and earth, and repair
if necessary.
Code No. 41 Injector systemProbable cause
Range of Check

Engine speed is approx. 50–1,000 r/min

The throttle position sensor output voltage is 1.15 V or less.

Actuator test by MUT-II is not carried out.
Set conditions

Surge voltage of injector coil is not detected for 4 seconds.
Malfunction of the injector

Improper connector contact, open or short-circuited
harness wire of the injector circuit

Malfunction of the engine-ECU
OK
Check trouble symptom.NGCheck the harness wire between the
resistor and the injector connector, and
repair if necessary.
Check the injector control circuit.
(Refer to P.13-55, INSPECTION PRO-
CEDURE 50.)OK
OK
Measure at the injector connectors
A-53, A-54, A-55, A-56

Disconnect the connector, and
measure at the harness side.

Voltage between 1 and earth
(Ignition switch: ON)
OK:System voltageNGCheck the following connector:
A-125NG
Repair
OK
Measure at the resistor connector
A-125.

Disconnect the connector, and
measure at the harness side.

Voltage between 3 and earth
(Ignition switch: ON)
OK:System voltageNGCheck the harness wire between the
control relay and the resistor connector,
and repair if necessary.
Check the injector. (Refer to P.13-34.)*
Check the resistor. (Refer to P.13-34.)*NG
Replace
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).

MPI – Troubleshooting13-16
Code No. 44 Ignition coil and power transistor unit systemProbable cause
Range of Check

Engine speed is approx. 50–4,000 r/min

Engine is not cranking.
Set conditions

Abnormal rotation due to misfire is detected by crank angle sensor (Either one
of coils fails).
Malfunction of the ignition coil

Improper connector contact, open or short-circuited
harness wire of the ignition primary circuit

Malfunction of the engine-ECU
OK
OK
Check trouble symptom.
Measure at the ignition coil connectors
A-110, A-111

Disconnect the connector, and
measure at the harness.
1. Voltage between 1 and earth
(Ignition switch: ON)
OK: System voltage
2. Voltage between 3 and earth
(Engine: Cranking)
OK: 0.5–4.0 V
3. Continuity between the 2 and earth
OK: Continuity1. NGCheck the following connectors:
B-65, B-76OKCheck trouble symptom.
NG
Check the harness wire between the
ignition coil and ignition switch connec-
tor, and repair if necessary.
2. NGCheck the following connector: B-59NG
Repair
NG
Check the harness wire between the
engine-ECU and ignition coil connector.OKReplace the engine-ECU.
NG
Repair
3. NG
Check the harness wire between the
ignition coil connector and earth, and
repair if necessary.
Check the following connectors:
A-110, A-111NG
Repair
Check trouble symptom.
NG
Check the following items.

Check the spark plugs, spark plug
cables.

Check the compression pressure.
NG
Repair
Check the ignition coil. (Refer to
GROUP 16 – IGNITION SYSTEM.)NG
Replace
OK
OK

MPI – Troubleshooting13-17
Code No. 64 Alternator FR terminal systemProbable cause
Range of Check

Engine speed is approx. 50 r/min or more
Set Conditions

The input voltage from the alternator FR terminal is higher than 4.5 V for 20 seconds.
Open circuit in alternator FR terminal circuit

Malfunction of the engine-ECU
Measure at the alternator connector A-05.

Connect the connector. (Use the test harness: MB991519.)

Voltage between 4 (blue clip) and earth
(Engine: Idling)
(Radiator fan: Stopped)
(Headlamp: OFF → ON)
(Brake lamp: OFF → ON)
(Rear window defogger switch: OFF → ON)
OK:Voltage drops 0.2 to 3.5 VOKReplace the engine-ECU.
NG
Measure at the alternator connector A-05.

Disconnect the connector, and measure at the harness side.

Voltage between 4 and earth
(Ignition switch: ON)
OK:4.8 – 5.2 VNGCheck the following
connectors: B-60, A-88NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire
between the engine-ECU
and the alternator con-
nector.NG
Repair
OK
Replace the engine-ECU.
OK
Check the following connector: A-05NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between the engine-ECU and the alternator
connector.NG
Repair
OK
Replace the alternator.

MPI – Troubleshooting13-38
INSPECTION PROCEDURE 26
Idle position switch system
Probable cause
The idle position switch inputs the condition of the accelerator pedal, i.e. whether
it is depressed or released (HIGH/LOW), to the engine-ECU.
The engine-ECU controls the idle speed control servo based on this input.
Maladjustment of the accelerator cable

Maladjustment of the fixed SAS

Maladjustment of the idle position switch and throttle
position sensor

Improper connector contact, open or short-circuited
harness wire

Malfunction of the engine-ECU
Check the idle position switch. (Refer to P.13-30.)*NGReplace the throttle position sensor.
OK
Measure at the throttle position sensor connector A-16.

Disconnect the connector, and measure at the harness side.

Voltage between 3 and earth (Ignition switch: ON)
OK:4 V or higher

Continuity between 4 and earth
OK:ContinuityNGCheck the following
connector: B-62NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between engine-ECU and throttle position
sensor connector.
OK
Replace the engine-ECU.
NG
Repair
OK
Check the following
connector: A-16NG
Repair
OK
Check trouble symptom.
NG
Replace the engine-ECU.
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).
INSPECTION PROCEDURE 27
Ignition switch-ST system
Probable cause
The ignition switch-ST inputs a HIGH signal to the engine-ECU while the engine is
cranking.
The engine-ECU controls fuel injection, etc. during starting based on this input.
Malfunction of ignition switch

Improper connector contact, open or short-circuited
harness wire

Malfunction of the engine-ECU
Measure at the engine-ECU connector B-62.

Disconnect the connector, and measure at the harness side.
1. Voltage between 71 and earth (Ignition switch: START)
OK:8V
2. Continuity between 91 and earth
OK:Continuity1. NGCheck the following
connector: B-64NG
Repair
OK
Check trouble symptom.
NG
Check harness wire be-
tween the engine-ECU
and ignition switch con-
nector.NG
Repair
OK
Check the ignition switch.
2. NG
Check the harness wire between engine-ECU connector (terminal
No.91) and earth, and repair if necessary.
OK
Check the following
connector: B-62NG
Repair
OK
Check trouble symptom.
NG
Replace the engine-ECU.

MPI – Troubleshooting13-41
INSPECTION PROCEDURE 30
Fan motor relay system (Radiator fan, A/C condenser fan)
Probable cause
The engine-ECU turns on/off the built-in power transistor to control the fan motor
relay.
Malfunction of the fan motor relay

Malfunction of the fan motor

Malfunction of thermostat

Improper connector contact, open or short-circuited
harness wire

Malfunction of engine-ECU
NG
Check the engine coolant temperature sensor. (Refer to P.13-10,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 21.)
OK
Replace the engine-ECU.
NG
MUT-II Data list
21 Engine coolant temperature sensor
OK:The engine coolant temperature agrees with the reading
of MUT-II when measured with the engine idling in warm
condition.OKCheck the thermostat.NG
Replace
OK
Check trouble symptom.
OK
Check the following connector: B-60NG
Repair NG
Check the A/C condenser fan circuit. (Refer to Electrical Wirings.)
NG
Measure at the engine-ECU connector B-60.

Disconnect the connector, and measure at the harness side.

Check the A/C condenser fan for operating condition.
(Ignition switch: ON)
OK:A/C condenser fan is stationary.

Voltage between each of 32 and 34 and earth
(Ignition switch: ON)
OK:System voltage

Short the terminal 32 to earth. (Ignition switch: ON)
OK:A/C condenser fan operates at high speed.

Short the terminal 34 to earth. (Ignition switch: ON)
OK:A/C condenser fan operates at low speed.
Check trouble symptom.
OK
OK
Check the following connector: B-59NG
Repair
Measure at the engine-ECU connector B-59.

Disconnect the connector, and measure at the harness side.

Check the radiator fan for operating condition.
(Ignition switch: ON)
OK:Radiator fan is stationary.

Voltage between each of 20 and 21 and earth
(Ignition switch: ON)
OK:System voltage

Short the terminal 20 to earth.
(Ignition switch: ON)
OK:Radiator fan operates at high speed.

Short the terminal 21 to earth.
(Ignition switch: ON)
OK:Radiator fan operates at low speed.NGCheck the radiator fan circuit. (Refer to Electrical Wirings.)

MPI – Troubleshooting13-56
DATA LIST REFERENCE TABLE
Item
No.Inspection
itemInspection contentsNormal conditionInspection
procedure
No.Reference
page
11Oxygen
sensorEngine:After having
warmed up
Air/fuel mixture is
made leaner when de-
When at 4,000 r/min,
engine is suddenly
decelerated200 mV or lessProcedure
No. 3113-42
made leaner when de-
celerating, and is made
richer when racing.
When engine is
suddenly raced600 – 1,000 mV
Engine:After having
warmed up
The oxygen sensor
si
gnal is used to check
Engine is idling400 mV or less
(Changes)
signal is used to check
the air/fuel mixture
ratio, and control
condition is also
checked by the ECU.2,500 r/min600 – 1,000 mV
12Air flow
sensor*
Engine coolant
tem
perature: 80 –
Engine is idling17 – 43 Hz––
sensor
TION-IV>temperature: 80
95C

Lamps, electric
li f d ll
2,500 r/min46 – 86 Hzp
cooling fan and all
accessories: OFF

Transmission:
Neutral (A/T:
P range)Engine is racedFrequency
increases in
response to
racing
12Air flow
sensor*
Engine coolant
tem
perature: 80 –
Engine is idling12 – 38 Hz––
sensor
TION-V, VI>temperature: 80
95C

Lamps, electric
li f d ll
2,500 r/min36 – 76 Hzp
cooling fan and all
accessories: OFF

Transmission:
Neutral (A/T:
P range)Engine is racedFrequency
increases in
response to
racing
13Intake air
temperature
sensor
Ignition switch: ON or
with engine runningWhen intake air
temperature is –20C–20CCode No.
1313-9
sensorWhen intake air
temperature is 0C0C
When intake air
temperature is 20C20C
When intake air
temperature is 40C40C
When intake air
temperature is 80C80C
NOTE
*: In a new vehicle [driven approximately 500 km or less], the air flow sensor output frequency is sometimes
10% higher than the standard frequency.

MPI – Troubleshooting13-62
Item
No.Reference
page Inspection
procedure
No. Normal condition Inspection contents Drive contents Inspection
item
20Radiator
fan
(HIGH),
condenser
fan
(HIGH)*
1
Drive the fan
motors (for
radiator and
condenser*
1)

Ignition switch: ON

A/C switch: ON*1Fan motors
operate at high
speed.Procedure
No. 3013-40
21Radiator
fan
(LOW),
condenser
fan
(LOW)*
1
Drive the fan
motors (for
radiator and
condenser*
1)

Ignition switch: ON

A/C switch: ON*1Fan motors
operate at low
speed.
36*2Secondary
air control
solenoid
valveTurn solenoid
valve from
OFF to ON.Ignition switch: ONSound of opera-
tion can be heard
when solenoid
valve is driven.Procedure
No. 3613-46
37*2A/C con-
denser fan
(HIGH)Drive A/C
condenser fan
motorIgnition switch: ONA/C condenser
fan motor oper-
ates at high
speed.Procedure
No. 3013-41
38*2A/C con-
denser fan
(LOW)Drive A/C
condenser fan
motorIgnition switch: ONA/C condenser
fan motor oper-
ates at low speed.
NOTE
*1: EVOLUTION-IV and EVOLUTION-V
*2: EVOLUTION-VI

MPI – Troubleshooting13-63
ENGINE-ECU INSPECTION
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: ONSystem voltage
valve
Engine: Cranking to idling (within about two minutes)0 – 3 V to sytem
voltage
4Stepper motor coil (A1)Engine: Immediately after engine has been started
f
or warming up
Changes repeatedly
f
rom system voltage
17Stepper motor coil (A2)
for warming upfrom system voltage
to 0 – 6 V and from 0
6 V to system5Stepper motor coil (B1)– 6 V to system
voltage.
18Stepper motor coil (B2)
6Secondary air control
solenoid valveIgnition switch: ONSystem voltage
8Fuel pump relayIgnition switch: ONSystem 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: ONSystem voltage
valve
Engine: At idle after having been warmed up (when
premium gasoline is used)0 – 3 V
12Power supplyIgnition switch: ONSystem 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)System voltage
Fan at high speed (coolant temperature: 105C or
above)0 – 3 V