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Mitsubishi Lancer Evolution 8. Manual - part 158

MPI – TROUBLESHOOTING

13A-18

Check connector B-25

B-25 O2 sensor connector
measurements
• Undo connector, and take

measurement on sensor side

• Resistance across 1 - 3
OK: 11 ~ 18

Ω

B-25 O2 sensor connector
measurement
• Undo connector, then take

harness measurement

• Ignition switch: ON
• Voltage across 1 - earth
OK: Battery voltage

C-49 Engine ECU connector
measurements
• Measure engine ECU terminal

voltage

• Ignition switch: ON
• Voltage across 3 – earth
OK: Battery voltage

Check connector C-49

Check harness between O2
sensor and Engine control relay
• Check to see if power supply

wire is damaged

Check harness between O2
sensor and Engine ECU
• Check to see if earth wire is

damaged

Confirm fault symptoms

Replace engine ECU

Replace O2 sensor

Check connector B-19X

Check and repair harness
between O2 sensor ~ Engine
control relay
• Check to see if power supply

cable is broken or has short
circuit.

Check connector C49

Check harness between O2
sensor and Engine ECU
• Check to see if earth wire is

broken or has short circuit.

Replace engine ECU

Intermittent malfunction (ref.
Chapter 00 – Intermittent
Malfunctions)

Code No. P0135 O2 Sensor Heater System

Probable causes

Inspection Conditions
• Engine cooling water temperature approx. 20ºC or more
• O2 sensor heater ON
• Engine speed at least 50rpm
• A/C relay: OFF, Radiator Fan: OFF
• Battery voltage 11 ~ 16V
Evaluation conditions
• With O2 sensor heater current 0.2A or less, or 3.5A or more,

for 4 seconds

• O2 sensor heater malfunction
• O2 sensor heater circuit broken, short-circuit, or poor

connector contact

• Engine ECU malfunction

Repair

MPI – TROUBLESHOOTING

13A-19

MUT-II/III diagnosis codes
• Have any diagnosis codes other

than code no. P0170 been
output?

MUT-II/III service data
• No.12 AFS
• No.13 Intake air temp. sensor
• No.21 Water temp. sensor
• No.25 Atmospheric air pressure

sensor

(ref. P.13A-83)
<For reference>
When all service data values are
correct, proceed to OK.
If there are one or more abnormal
service data values, proceed to
NG

Check air being taken in via
intake hose and inlet manifold

Check for any exhaust gas leaks
from the exhaust manifold

Check for dirt on throttle body (in
the area of throttle valve)

MUT-II/III service data
• No.11: O2 service data
(ref. P.13A-83)

Check purge control solenoid
valve component (ref. Chapter 17
– Emission Control)

Check fuel pressure
(ref. P.13D-109) *

Replace injector

Confirm fault symptoms

Replace engine ECU

Table showing diagnosis codes
(ref. P.13A-8)

When abnormal service data
values occur, go to the checking
procedures relevant to the
particular sensor diagnosis codes
(ref. P.13A-5)

Clean throttle body (area of
throttle valve) (ref. P.13D-107)*

Check Code No.P0130: O2
Sensor System (ref. P.13A-19)

Replace purge control solenoid

Intermittent malfunction (ref.
Chapter 00 – Intermittent
Malfunctions)

* Refer to ’01 Lancer Evolution VII Workshop Manual (No.1036K02)

Code No. P0170 Fuel System Abnormality

Probable causes

Inspection Conditions
• Engine Air-fuel ratio learning
Evaluation conditions
• At least 5 second duration when injected fuel correction value is

abnormally low

or
• At least 5 second duration when injected fuel correction value is

abnormally high

• Fuel supply system malfunction
• O2 sensor malfunction
• Intake air temperature sensor malfunction
• Atmospheric air pressure sensor malfunction
• Air flow sensor malfunction
• Purge control solenoid valve malfunction
• Engine ECU malfunction

YES

Repair

MPI – TROUBLESHOOTING

13A-20

MUT-II/III actuator test
• No.01: No.1 injector
OK: Idle condition changes

Intermittent malfunction (ref.
Chapter 00 – Intermittent
Malfunctions)

Replace No.1 injector

Check connector B-29

B-29 No.1 Injector connector
measurements
• Undo connector, take

measurement at harness

• Resistance across 1 – 2
OK: 2 ~ 3

Ω

B-29 No.1 Injector connector
measurements
• Undo connector, take

measurement at harness

• Ignition switch: ON
• Voltage across 1 – earth
OK: Battery voltage

Check harness between No.1
injector and register (used for
injectors)
• Check for damage to power

supply cable

Check harness between register
(used for injectors) and engine
control relay
• Check for damage to power

supply cable

Check connector C-49

Replace engine ECU

Check connector B-19X, B-129,
C-23

Check register (ref. P.13D-116) *

Check harness between No.1
injector and register (used for
injectors)
• Check if power supply cable is

broken or has short circuit

Check and repair harness
between register (used for
injectors) and engine control relay
• Check if power supply cable is

broken or has short circuit

Intermittent malfunction (ref.
Chapter 00 – Intermittent
Malfunctions)

Check harness between No.1
injector and engine ECU
• Check if output wire is broken,

has short circuit, or is damaged

C-49 Measure signal waveform at
engine ECU connector (using an
oscilloscope)
• Engine idling
• Voltage across 1 –earth
OK: Output waveform should be
as explained in P.13A-92
(Instructions for checks done
using oscilloscope)

* Refer to ’01 Lancer Evolution VII Workshop Manual (No.1036K02)

Code No.P0201 No.1 Injector System

Probable causes

Inspection Conditions
• Engine speed: 50 ~ 1,000rpm
• TPS output voltage 1.15V or less
• Not during MUTII/III forced drive (actuator test)
Evaluation conditions
• Injector coil surge voltage not detected for a 2 second

duration

• No.1 injector malfunction
• No.1 injector circuit broken, has short circuit, or poor

connector contact

• Engine ECU malfunction

Repair

MPI – TROUBLESHOOTING

13A-21

MUT-II/III actuator test
• No.02: No.2 injector
OK: Idle condition changes

Check connector B-28

B-28 No.2 Injector connector
measurements
• Undo connector, take

measurement at harness

• Resistance across 1 –2
OK: 2 ~ 3

Ω

B-28 No.2 Injector connector
measurements
• Undo connector, take

measurement at harness

• Ignition switch: ON
• Voltage across 1 – earth
OK: Battery voltage

Check harness between No.2
injector and register (used for
injectors)
• Check for damage to power

supply cable

Check harness between register
(used for injectors) and engine
control relay
• Check for damage to power

supply cable

Check harness between No.2
injector and engine ECU
• Check if output wire is broken,

has short circuit, or is damaged

C-49 Measure signal waveform
at engine ECU connector (using
an oscilloscope)
• Engine idling
• Voltage across 9 – earth
OK: Output waveform should be
as explained in P.13A-92
(Instructions for checks done
using oscilloscope)

Intermittent malfunction (ref.
Chapter 00 – Intermittent
Malfunctions)

Check and repair harness
between register (used for
injectors) and engine control relay
• Check if power supply cable is

broken or has short circuit

Check harness between No.2
injector and register (used for
injectors)
• Check if power supply cable is

broken or has short circuit

Check register (ref. P.13D-116) *

Check connectors B-19X, B-
129, C-23

Replace No.2 injector

Replace engine ECU

Check connector C-49

* Refer to ’01 Lancer Evolution VII Workshop Manual (No.1036K02)

Code No.P0202 No.2 Injector System

Probable causes

Inspection Conditions
• Engine speed: 50 ~ 1,000rpm or less
• TPS output voltage 1.15V or less
• Not during MUTII/III forced drive (actuator test)
Evaluation conditions
• Injector coil surge voltage not detected for a 2 second

duration

• No.2 injector malfunction
• No.2 injector circuit broken, has short circuit, or poor

connector contact

• Engine ECU malfunction

Repair

Content .. 156 157 158 159 ..