inspection procedure 13 MITSUBISHI MONTERO 2000 Service Owner's Guide

GDI -Troubleshooting 13A-92
Inspection procedure 18
Too high CO and HC concentration when idling
Probable cause
The cause is probably an incorrect air/fuel ratioDMalfunction of air/fuel ratio control system
DDeterioration of the catalyst
MUT-
IISelf-Diag code
Is a diagnosis code displayed?Ye s(Refer to P.13A-15, INSPECTION CHART FOR DIAGNOSIS
CODES.)
No
Check ignition timing. (Refer to GROUP 11A - Engine Adjustment.)NGCheck that the crankanglesensor andtiming beltcover are properly
installed.
OK
MUT-
IIData list
21 Engine coolant temperature sensor (Refer to P.13A-105.)NGCheck theengine coolant temperaturesensor. (Refer to P.13A-22,
code No. P0115.)
OK
MUT-
IIData list
13 Intake air temperature sensor (Refer to P.13A-105.)NGCheck the intake air temperature sensor. (Refer to P.13A-21, code
No. P0110.)
OK
MUT-
IIData list
25 Barometric pressure sensor (Refer to P.13A-105.)NGCheck the barometric pressure sensor. (Refer to P.13A-19, code
No. P0105.)
OK
NG
Check the oxygen sensor (front) system. (Refer to P.13A-31, code
No. P0130.)
OK
MUT-
IIData list
11 Oxygen sensor (front)
OK:
0 - 400 mV and 600 - 1,000 mV alternates when the
engine is idling(wait for four minutes after theengine
started).OKReplace the oxygen sensor (front).
Check trouble symptom.
NGNG
Measure fuel high-pressure between the fuel pump (highpressure)
and injector. (Refer to P.13A-224.)NG
Repair
OK
Check ignition coil spark for each cylinder.
(1) Remove the ignition coil.
(2) Install a new sparkplug to the removed ignitioncoil.
(3) Disconnect the injector intermediate connector.
Caution
Never touch the connector terminal as approx. 100 V is applied to the injector, or you are seriously injured.
(4) Earth the sparkplug electrodesecurely.
(5) Check that the sparkplug igniteswhen theengine iscranked.
NG
Replace the ignition coil.
OK
Check all the following items:
DSparkplug
DEGR system
DCompression pressure
DClogged fuel filter or line
OK
To the nextpage
OK
MUT-
IIData list
59 Oxygen sensor (rear) (Refer to P.13A-78.)
DTransmission: 2nd gear
DDriving with throttle widelyopen
OK:
600 - 1,000 mVNGCheck the oxygen sensor (rear) system. (Refer to P.13A-31, code
No. P0136.)
MUT-
IIData list
11 Oxygen sensor (front)
OK:
600 - 1,000 mV when theengine is suddenlyraced


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GDI -Troubleshooting 13A-94
Inspection procedure 19
Low alternator output voltage (approx.12.3 V)
Probable cause
The cause is probably a malfunction of the alternator or one of the problems
listed at right.DMalfunction of the charging system
DOpen circuit between the alternator G terminal and
the engine-ECU
DMalfunction of the engine-ECU
NG
Repair
OK
Replace the engine-ECU.
OK
Check the alternator. (Refer to GROUP
16 - Charging System.)
OK
Check the following connectors:
B-41, B-59, D-119
Measure at the alternator connector
B-59.
DConnect the connector. (Use the
test harness MB991519)
DVoltage between 1 (black clip)
and earth
(Engine: Idling)
(Radiator fan: Not operating)
(Headlamp: OFF®ON)
(Stoplamp: OFF®ON)
(Rear defogger switch: OFF®
ON)
OK:
Voltage increased by
0.2 - 3.5 V.NGMeasure at the alternator connector
B-59.
DDisconnect the connector, and
measure at the harness side.
DDisconnect the engine-ECU
connector.
DContinuity between 1 and earth
OK:
No continuityNGCheck the harness wire between the
alternator and the engine-ECU, and
repair if necessary.
Inspection procedure 20
Idling speed is improper when A/C is operating
Probable cause
If the engine-ECU detects that the air conditioner is on, it activates the throttle control
servo to control idle-up operation.
The A/C-ECU judges if theloadcaused by air conditioner operation ishigh or low,
and converts it to voltage signal (high or low voltage) and inputs the signal to the
engine-ECU.
Based on this voltage signal, the engine-ECU controls the idle-up speed (forhigh
or low load).DMalfunction of the A/C control system
DImproper connector contact,opencircuit or
short-circuited harness wire
DMalfunction of the engine-ECU
NG
Repair
Measure at the engine-ECU connector D-117.
DConnect the connector.
DVoltage between 65 and earth (Engine: at idle, outside air
temperature: 25_C or more)
OK:
0 - 3 V [When A/C is MAX. COOL condition (when the
load by A/C is high)]
System voltage [When A/C is MAX. HOT condition (when
the load by A/C islow)]OKCheck the following connector:
D-117
OK
Check trouble symptom.
NG
Replace the engine-ECU.
NG
Check the A/C system. (Refer to GROUP 55 - On-vehicle Service.)


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GDI -Troubleshooting 13A-95
Inspection procedure 21
A/C condenser fan is inoperative
Probable cause
The fan motor relay is controlled by turning on and off the power transistor in
the engine-ECU.DMalfunction of the A/C condenser fan relay.
DMalfunction of the condenser fan motor.
DImproper connector contact,opencircuit or
short-circuited harness wire
DMalfunction of the engine-ECU
OK
Replace the engine-ECU.NG
Repair
OK
Check the trouble symptoms.
Check the following connector:
D-116
Measure at the engine-ECU connector D-116.
DDisconnect the connector, and measure at the harness side.
DCheck condition of the condenser fan.
(Ignition switch: ON)
OK:
Fan stops.
DThe voltage between 18 and earth
(Ignition switch: ON)
OK:
System voltage
DConnect a jumper cable between 18 and earth.
(Ignition switch: ON)
OK:
A/C condenser fan rotates.NGCheck the condenser fan circuit. (Refer to ELECTRICAL WIRING)
NG


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GDI -Troubleshooting 13A-96
Inspection procedure 22
Clutch switch system malfunction
Probable cause
The clutchpedalswitch sends a signal indicating clutchpedal depression to the
engine-ECU. The engine-ECU controls the fuel injection properly according to this
signal, thus prevents the fluctuation of theenginespeed during shift change.DMalfunction of the clutch switch
DOpen circuit or short-circuited harness wire in the clutch
switch circuit
DMalfunction of the engine-ECU
NG
Repair
NG
Repair
OK
Replace the engine-ECU.
(2) NG
OK
Check the trouble symptoms.
NG
Replace the engine-ECU.
OK
Check the following connector:
D-137
Check the harness wire between the
clutch switch connector and the earth,
and repair if necessary.
Check the trouble symptoms.
Check the harness wire between the
engine-ECU and the clutch switch con-
nector.
Measure at the clutch switch connector
D-137.
DDisconnect the connector, and
measure at the harness side.
(1) Voltage between 2 and earth
(Ignition switch: ON)
OK:
System voltage
(2) Continuity between 1 and earth
OK:
Continuity(1) NGCheck the following connector:
D-26 , D-124 , D-117,
E-10OK NG
Replace
Repair
OK
Check the clutch switch. (Refer to
P.13A-233.)
NG
NG
Inspection procedure 23
GDI ECO indicator lamp does not illuminate.
Probable cause
If the GDI ECO indicator lampdoes notilluminate after turningswitch, the causes
listed in the right column are suspected.DBurned-out GDI ECO indicator lamp bulb
DOpen circuit or short-circuited harness wire in the GDI
ECO indicator lampcircuit
DMalfunction of the engine-ECU
DMalfunction of the GDI ECO indicator lamp-ECU
NG
Repair
Measure at the engine-ECU connector D-116.
DDisconnect the connector, and measure at the harness side.
DEarth terminal 14 (Ignition switch: ON)
OK:
The GDI ECO indicator lamp illuminates.OKCheck the following connector:
D-116
OK
Check trouble symptom.
NG
Replace the engine-ECU.
NG
Check the following connectors:
E-13, E-112
Check trouble symptom.
Check the harness wire between the GDI ECO indicator lamp-ECU
and engine-ECU.
Check the relative circuit of GDI ECO indicatorlamp.(Refer to
GROUP 54A - Troubleshooting.)NG OK
OK NG
NG
Repair
Repair


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GDI -Troubleshooting 13A-97
Inspection procedure 24
GDI ECO indicator lamp remains illuminated and does
not go off.
Probable cause
If the GDI ECO indicator lampdoes not go off duringhigh load operation, thecauses
listed in the right column are suspected.DShort circuit between the GDI ECO indicatorlamp and
engine-ECU
DMalfunction of the engine-ECU
DMalfunction of the GDI ECO indicator lamp-ECU
OK
Replace the engine-ECU.
Measure at GDI ECO indicator lamp-ECU connector E-112.
DDisconnect the connector, and measure at the harness side.
DDisconnect the engine-ECU connector.
DContinuity between terminal 3 and earth
OK:
No continuityNGCheck the harness wire between the GDI ECO indicator
lamp-ECU and engine-ECU, and repair if necessary.
OK
Check the relative circuit of GDI ECO indicatorlamp.(Refer to
GROUP 54A - Troubleshooting.)


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GDI -Troubleshooting 13A-98
Inspection procedure 25
Engine-ECU power supply and earth circuit system
Probable cause
The cause is probably a malfunction of the engine-ECU or one of the problems
listed at right.DOpen circuit or short-circuited harness wire in the
engine-ECU power supply circuit
DOpen circuit or short-circuited harness wire in the
engine-ECU earth circuit
DMalfunction of the engine-ECU
NG
RepairOK
Check the ignition switch. (Refer to
GROUP 54.)
(2), (3) NGCheck the harness wire between the
engine-ECU and engine controlrelay,
and repair if necessary.
(4) NG
Check the harness wire between the
engine-ECU and earth, and repair if nec-
essary.
(5) NG
NG
Repair
OK
Check the trouble symptoms.NGCheck the harness wire between the
engine-ECU and the battery, and repair
if necessary.
NG
Repair
NG
Replace the engine-ECU.
OK
Check the trouble symptoms.
OK
Check the following connectors:
D-117, D-118
Check the following connectors:
D-27, D-31 , E-13OK
Check the trouble symptoms.NGCheck the harness wire between the
engine-ECU and ignition switch, and re-
pair if necessary.
Measure at the engine-ECU connectors
D-117, D-118.
DDisconnect the connector, and
measure at the harness side.
(1) Voltage between 99 and earth
(Ignition switch: ON)
OK:
System voltage
(2) Voltage between 57 and earth
OK:
System voltage
(3) Voltage between 47, 59 and
earth (Ignition switch: ON)
OK:
System voltage (When ter-
minal 57 is shorted to
earth)
(4) Continuity between 46, 58 and
earth
OK:
Continuity
(5) Voltage between 60 and earth
OK:
System voltage(1) NGCheck the following connector:
D-208, D-223, E-13NG
Repair
Check the following connector:
D-14NG
Repair
Check the trouble symptoms.OK
NG


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GDI -Troubleshooting 13A-99
Inspection procedure 26
Engine control relay and ignition switch-IG system
Probable cause
When the ignition switch ON signal is input to the engine-ECU, the engine-ECU
turns on theengine controlrelay.
This causes system voltage to be supplied to the engine-ECU and to the
sensors and actuators.DMalfunction of the ignition switch
DMalfunction of the engine controlrelay
DOpen circuit or short-circuited harness wire of the
engine controlrelay circuit
DMalfunction of the engine-ECU
OK
Check the trouble symptoms.NGCheck the harness wire between the
battery and theengine controlrelay, and
repair if necessary.
OK
Check the engine-ECU power supply
and earth circuit system. (Refer to
P.13A-98, Inspection procedure 25.)
OK
Measure at the engine controlrelay con-
nector B-25X.
DDisconnect the connector, and
measure at the harness side.
DVoltage between 2, 3 and earth
OK:
System voltageNGCheck the following connector:
D-143NG
Repair
Check theengine controlrelay. (Refer
to P.13A-227.)NG
Replace
Inspection procedure 27
Ignition switch-ST system
Probable cause
The ignition switch-ST outputs a HIGH signal to the engine-ECU while the
engine iscranking.
The engine-ECU uses this signal to carry out functions such as fuel injection
control during starting.DMalfunction of the ignition switch
DOpen circuit or short-circuited harness wire of the
ignition switch circuit
DMalfunction of the engine-ECU
NG
RepairOK
Check the ignition switch. (Refer to
GROUP 54.)
NG
Replace the engine-ECU.
OK
Check the trouble symptoms.
OK
Check the following connector:
D-117NG
RepairOK
Check the trouble symptoms.NGCheck the harness wire between the
engine-ECU and the ignition switch.
Measure at the engine-ECU connector
D-117.
DDisconnect the connector, and
measure at the harness side.
DVoltage between 68 and earth
(Ignition switch: START)
OK:
8 V or moreNGCheck the following connectors:
C-01, E-113, E-114NG
Repair


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GDI -Troubleshooting 13A-100
Inspection procedure 28
Accelerator pedal position switch system
Probable cause
The accelerator pedal positionswitch detects that the acceleratorpedal isfully closed,
and sends a signal to the engine-ECU. The engine-ECU controlsidle speed,based
on this signal.DMaladjustment of the accelerator cable
DMaladjustment of the accelerator pedal positionswitch
DOpen circuit or short-circuited harness wire in the
accelerator pedal positionswitch system, or poor
connector contact
DMalfunction of the engine-ECU
NG
Repair
NG
Repair
Check the acceleratorpedal positionswitch. (Refer to P.13A-230.)NGReplace the accelerator pedal positionsensor assembly.
OK
Measure at accelerator pedal positionsensor connector D-135.
DDisconnect the connector, and measure at the harness side.
DVoltage between terminal 4 and earth
(Ignition switch: ON)
OK:
4 V or more
DContinuity between terminal 5 and earth
OK:
ContinuityNGCheck the following connector:
D-118
OK
Check trouble symptom.
NG
Check the harness wire between the engine-ECU and accelerator
pedal positionsensor.
OK
Check the following connector:
D-135NG
Repair
OK
Check trouble symptom.NGReplace the engine-ECU.
OK


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GDI -Troubleshooting 13A-101
Inspection procedure 29
Fuel pump (low pressure) system
Probable cause
The engine-ECU turns on the fuelpumprelay while theengine iscranking or running,
and supplies power source to the fuelpump(low pressure).DMalfunction of the fuel pumprelay
DMalfunction of the fuel pump(low pressure)
DOpen circuit or short-circuited harness wire in the fuel
pump(low pressure) circuit, or poor connector contact
DMalfunction of the engine-ECU
Check trouble symptom.NGCheck the harness wire between the
fuel pump(low pressure) and earth, and
repair if necessary.
NG
RepairOK
Check trouble symptom.NGCheck the harness wire between the
fuel pumprelay and engine-ECU, and
repair if necessary.
NG
RepairOK
NG
RepairOK
Check the ignition switch. (Refer to
GROUP 54 - Ignition Switch.)
(2) NGCheck the following connector:
F-11
MUT-
IIActuator test
07 Fuel pump(Refer to P.13A-110.)OK
Normal
NG
Check the fuelpumprelay. (Refer to
P.13A-227.)NG
Replace
OK
Measure at fuel pumprelay connector
B-27X.
DDisconnect the connector, and
measure at the harness side.
DVoltage between terminals 3, 4 and
earth
(Ignition switch: ON)
OK:
System voltageNGCheck the following connectors:
D-208, D-213, E-10NG
Repair
OK
Check trouble symptom.NGCheck the harness wire between the
fuel pumprelay and ignition switch.
OK
Measure at engine-ECU connector
D-116.
DDisconnect the connector, and
measure at the harness side.
DVoltage between terminal 21 and
earth (Ignition switch: ON)
OK:
System voltageNGCheck the following connector:
B-27X
OK
Measure at engine-ECU connector
D-116.
DDisconnect the connector, and
measure at the harness side.
DShort circuit between terminal 21
and earth (Ignition switch: ON)
OK:
The fuel pump operates(its
operation sound can be
heard).OKCheck the following connector:
D-116NG
Repair
OK
Check trouble symptom.NGReplace the engine-ECU.
NG
Measure at fuel pump(low pressure)
connector G-12.
DDisconnect the connector, and
measure at the harness side.
(1) Voltage between terminal 5 and
earth
(Ignition switch: ON)
OK:
System voltage
(2) Continuity between 4 and earth
OK:
Continuity(1) NGCheck the following connectors:
B-27X, D-124, E-13, F-11NG
Repair
OK
Check trouble symptom.NGCheck the harness wire between the
fuel pumprelay and fuelpump(low
pressure), and repair if necessary.
OK
Check the following connector:
G-12NG
Repair
OK
Check trouble symptom.
NG
Replace the fuel pump(low pressure).


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GDI -Troubleshooting 13A-102
Inspection procedure 30
Power steering fluid pressure switch system
Probable cause
The power steering fluid pressure switch sends a signal to the engine-ECU according
to power steering load.
Based on this signal, the engine-ECU controls the throttle control servo so thatidle
speed increases when the power steering is in operation.DMalfunction of the power steering fluid pressure switch
DOpen circuit or short-circuited harness wire in the power
steering fluid pressure switch circuit, or poor connector
contact
DMalfunction of the engine-ECU
NG
NG
RepairOK
Replace the engine-ECU.
NG
Repair
Check the power steering fluid pressure switch. (Refer to GROUP
37A - On-vehicle Service.)NG
Replace
OK
Measure at power steering fluid pressure switch connector B-51.
DDisconnect the connector, and measure at the harness side.
DVoltage between terminal 1 and earth
(Ignition switch: ON)
OK:
System voltageNGCheck the following connector:
D-117
OK
Check trouble symptom.
Check the harness wire between the engine-ECU and power steer-
ing fluid pressure switch.NG
RepairOK
OK
Check the following connector:
B-51
Check trouble symptom.NG
Inspection procedure 31
A/C switch and A/C relay system
Probable cause
If the engine-ECU receives a ‘A/C on’ signal, it operates the throttle control servo
and A/C compressor magnetic clutch so thatidlespeed increases.DMalfunction of the A/C control system
DMalfunction of the A/C switch
DOpen circuit or short-circuited harness wire in the A/C
switch circuit, or poor connector contact
DMalfunction of the engine-ECU
NG
NG
RepairOK
Check trouble symptom.
NG
Replace the engine-ECU.
Service the A/C compressor relay. (Refer to GROUP 55 - On-ve-
hicle Service.)NG
Replace
OK
Measure at engine-ECU connectors D-116, D-118.
DDisconnect the connector, and measure at the harness side.
DVoltage between terminals 20, 83 and earth
(Ignition switch: ON)
OK:
0-3V
(A/C switch: OFF)
System voltage
(A/C switch: ON)
DConnect terminal 20 to earth.
(Ignition switch: ON, A/C switch: ON)
OK:
A/C compressor clutch turns on.OKCheck the following connectors:
D-116, D-118
Check the A/C system. (Refer to GROUP 55 - On-vehicle Service.)


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