1999 MITSUBISHI LANCER EVOLUTION VI relay

MPI – Troubleshooting13-44
INSPECTION PROCEDURE 32
Ignition circuit system
Probable cause
The engine-ECU interrupts the ignition coil primary current by turning the power transistor
inside the engine-ECU ON and OFF.
Malfunction of ignition switch.

Improper connector contact, open or short-circuited
harness wire

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

Disconnect the connector and measure at the harness side.
1. Voltage between 1 and earth (Ignition switch: ON)
OK:System voltage
2. Continuity between 2 and earth
OK:Continuity1. NGCheck the following
connectors: B-65, B-76NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire
between ignition coil and
ignition switch connector.NG
Repair
OK
Check the ignition switch. 2. NG
Check the harness wire between ignition coil connector and earth,
and repair if necessary.
OK
Check the following
connectors:
A-110, A-111NG
Repair
OK
Check trouble symptom.NGCheck ignition coil and power transistor unit system. (Refer to
P.13-16, INSPECTION PROCEDURE FOR DIAGNOSIS CODE
44.)
INSPECTION PROCEDURE 33
Idle speed control (ISC) servo (Stepper motor) system
Probable cause
The engine-ECU controls the intake air volume during idling by opening and closing
the servo valve located in the bypass air passage.
Malfunction of ISC servo

Improper connector contact, open or short-circuited
harness wire

Malfunction of the engine-ECU
Check the ISC servo.NG
Replace
OK
Measure at the ISC servo connector A-18.

Disconnect the connector and measure at the harness side.

Voltage between 2 and earth, and 5 and earth (Ignition switch:
ON)
OK:System voltageNGCheck the harness wire between control relay and ISC servo con-
nector, and repair if necessary.
OK
Measure at the engine-ECU connector B-59.

Disconnect the connector, measure at the harness side.

Voltage between each of 4, 5, 17, 18 and earth (Ignition switch:
ON)
OK:System voltageNGCheck the following
connector: A-18NG
Repair
OK
Check trouble symptom.
NG
Check harness wire between engine-ECU and ISC servo connector,
and repair if necessary.
OK
Check the following
connector: B-59NG
Repair
OK
Check trouble symptom.NGReplace the engine-ECU.

MPI – Troubleshooting13-45
INSPECTION PROCEDURE 34
Fuel pressure control valve system
Probable cause
The fuel pressure control valve switches the pressure introduction into the fuel pressure
regulator between the intake manifold and atmosphere.
Malfunction of solenoid valve

Improper connector contact, open or short-circuited
harness wire

Malfunction of engine-ECU
NGReplace the engine-ECU.
OK
Check trouble symptom.
NG
Check the harness wire between engine-ECU and solenoid valve
connector, and repair if necessary.
OK
Check trouble symptom.
OK
Check the following connector: B-59NG
Repair
OK
Measure at the engine-ECU connector B-59.

Disconnect the connector, and measure at the harness side.

Voltage between 3 and earth
(Ignition switch: ON)
OK:System voltageNGCheck the following connector: A-12NG
Repair NG
Check the harness wire between control relay and solenoid valve
connector, and repair if necessary.
OK
Measure at the fuel pressure control valve connector A-12.

Disconnect the connector, and measure at the harness side.

Voltage between 1 and earth
(Ignition switch: ON)
OK:System voltage
Check the fuel pressure control valve.NG
Replace
INSPECTION PROCEDURE 35
Waste gate solenoid valve
Probable cause
The waste gate solenoid valve controls the boost pressure introduced into the waste
gate actuator in the turbocharger.
Malfunction of solenoid valve

Improper connector contact, open or short-circuited
harness wire

Malfunction of engine-ECU
NGReplace the engine-ECU.
OK
Check trouble symptom.
NG
Check the harness wire between engine-ECU and solenoid valve
connector, and repair if necessary.
OK
Check trouble symptom.
OK
Check the following connector: B-59NG
Repair
OK
Measure at the engine-ECU connector B-59.

Disconnect the connector, and measure at the harness side.

Voltage between 11 and earth
(Ignition switch: ON)
OK:System voltageNGCheck the following connector: A-23NG
Repair NG
Check the harness wire between control relay and solenoid valve
connector, and repair if necessary.
OK
Measure at the waste gate solenoid valve connector A-23.

Disconnect the connector, and measure at the harness side.

Voltage between 2 and earth
(Ignition switch: ON)
OK:System voltage
Check the waste gate solenoid valve.
(Refer to Group 15 – On-vehicle service.)*NG
Replace
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).

MPI – Troubleshooting13-46
INSPECTION PROCEDURE 36
Secondary air control solenoid valve system
Probable cause
The secondary air control solenoid valve switches the pressure introduction into the
secondary air valve between the intake manifold and atmosphere.
Malfunction of solenoid valve

Improper connector contact, open or short-circuited
harness wire

Malfunction of engine-ECU
NGReplace the engine-ECU.
OK
Check trouble symptom.
NG
Check the harness wire between engine-ECU and solenoid valve
connector, and repair if necessary.
OK
Check trouble symptom.
NG
Check the harness wire between control relay and solenoid valve
connector, and repair if necessary.
OK
Check trouble symptom.
OK
Check the following connector: B-59NG
Repair
OK
Measure at the engine-ECU connector B-59.

Disconnect the connector, and measure at the harness side.

Voltage between 6 and earth
(Ignition switch: ON)
OK:System voltageNGCheck the following connectors:
A-127, A-88NG
Repair
OK
Measure at the secondary air control solenoid connector A-127.

Disconnect the connector, and measure at the harness side.

Voltage between 1 and earth
(Ignition switch: ON)
OK:System voltageNGCheck the following connector: A-88NG
Repair
Check the secondary air control solenoid valve.
(Refer to Group 15 – INTAKE AND EXHAUST.)*NG
Replace
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).

MPI – Troubleshooting13-49
INSPECTION PROCEDURE 41
MUT-II: Check if idling speed is unstable.
OK
MUT-II Data list
45 ISC servo position (Refer to P.13-60.)NGAdjust the basic idle speed. (Refer to P.13-30.)*
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
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.)
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.
OK
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
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
21 Engine coolant temperature sensor (Refer to P.13-21.)NGCheck the engine coolant temperature sensor system.
(Refer to P.13-10, INSPECTION PROCEDURE FOR DIAGNOSIS
CODE 21.)
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
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.)
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.)
NOTE
*: Refer to Workshop Manual for LANCER EVOLUTION-IV and EVOLUTION-V (Pub. No. S9806CNCP9).

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 – Troubleshooting13-53
INSPECTION PROCEDURE 45
Check the engine-ECU power supply and earth circuit.
Measure at the engine-ECU connectors, B-59, B-60, B-62.

Disconnect the connector and measure at the harness side
1. Voltage between 82 and earth (Ignition switch: ON)
OK:System voltage
2. Voltage between 38 and earth
OK:System voltage
3. Voltage between 12, 25 and earth (Ignition switch: ON)
OK:System voltage (when the terminal 38 is earthed)
4. Continuity between 13, 26 and earth
OK:Continuity
5. Voltage between 80 and earth
OK:System voltage1. NGCheck the following
connectors: B-65, B-76NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire
between engine-ECU and
ignition switch connector.NG
Repair
OK
Check the ignition switch. (Refer to GROUP 54.)
2, 3. NG
4. NG
Check the harness wire between engine-ECU and earth, and repair
if necessary.
5. NG
OK
Check the following
connectors:
B-59, B-60, B-62NG
Repair
OK
Check trouble symptom.
NG
Replace the engine-ECU.
Check the following connectors:
B-65, B-49, B-75, B-73NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between engine-ECU and battery, and
repair if necessary.
Check the harness wire between engine-ECU and control relay
connector, and repair if necessary.
INSPECTION PROCEDURE 46
Check fuel pump circuit.
Measure at the fuel pump connector D-18.

Disconnect the connector and measure at the harness side.

Continuity between 1 and earth
OK:ContinuityNGCheck the following connector:
D-04NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between fuel pump and earth, and repair
if necessary.
OK
Check the following connectors: D-04, B-64NG
Repair OKCheck trouble symptom.
NG
Check the harness wire between terminal for fuel pump drive and
fuel pump connector.NG
Repair
OK
Replace the fuel pump.

MPI – Troubleshooting13-54
INSPECTION PROCEDURE 46
Check fuel pump circuit.
Measure at the fuel pump relay connector D-18.

Disconnect the connector and measure at the harness side.

Continuity between 1 and earth
OK:ContinuityNGCheck the following connector:
D-04NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between fuel pump and earth, and repair
if necessary.
OK
Check the following connectors: A-123, B-64, D-18, D-32NG
Repair OKCheck trouble symptom.
NG
Check the harness wire between fuel pump and fuel pump relay
No.2 connector.NG
Repair
OK
Replace the fuel pump.
INSPECTION PROCEDURE 47
Check the fuel pump drive control circuit.
NG
Check the harness wire between the fuel pump relay and engine-
ECU connector.
OK
Check trouble symptom.
OK
Check trouble symptom.
NG
Check the harness wire
between fuel pump relay
and ignition switch con-
nector.NG
Repair
OK
Check the ignition switch. (Refer to GROUP 54.)OK
Check trouble symptom.
NG
Replace the engine-ECU.
NG
Repair
OK
Check the following connector: B-59
OK
Measure at the engine-ECU connector B-59.

Disconnect the connector and measure at the harness side.

Voltage between 8 and earth (Ignition switch: ON)
OK:System voltageNG
Measure at the fuel pump relay connector B-28.

Disconnect the connector and measure at the harness side.

Voltage between 3, 4 and earth (Ignition switch: ON)
OK:System voltageNGCheck the following
connectors: B-65, B-76NG
Repair
Check the following
connector: B-28NG
Repair

MPI – TroubleshootingMPI – Troubleshooting13-55
INSPECTION PROCEDURE 48
Check air flow sensor control circuit.
2, 3. NGCheck the following
connector: B-62NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire
between the engine-ECU
and air flow sensor con-
nector.NG
Repair
OK
Replace the engine-ECU.
OK
Check trouble symptom.
NG
Replace the air flow sensor.
NG
Repair
OK
Check the following connector: A-25
Measure at the air flow sensor connector A-25.

Disconnect the connector and measure at the harness side.
1. Voltage between 4 and earth (Ignition switch: ON)
OK:System voltage
2. Voltage between 3 and earth (Ignition switch: ON)
OK:4.8–5.2 V
3. Continuity between 5 and earth
OK:Continuity1. NGCheck the harness wire between the air flow sensor and control
relay connector, and repair if necessary.
INSPECTION PROCEDURE 49
Check throttle position sensor output circuit.
Measure at the engine-ECU connector B-62.

Connect the connector.

Voltage between 84 and earth (Ignition switch: ON)
OK:0.3–1.0 V (Throttle valve at idle position)
4.5–5.5 V (Throttle valve fully open)NGCheck the following
connector: B-62NG
Repair
OK
Check trouble symptom.
NG
Replace the engine-ECU.
OK
Check the harness wire between engine-ECU and throttle position
sensor connector, and repair if necessary.
INSPECTION PROCEDURE 50
Check injector control circuit.
Measure at the engine-ECU connector B-59.

Disconnect the connector and measure at the harness side.

Voltage between 1, 2, 14, 15 and earth (Ignition switch: ON)
OK:System voltageNGCheck the following
connectors:
A-53, A-54, A-55, A-56NG
Repair
OK
Check trouble symptom.
NG
Check the harness between engine-ECU and injector connector,
and repair if necessary.
OK
Check the following connector: B-59
OK
Check trouble symptom.
NG
Replace the engine-ECU.NG
Repair