2000 MITSUBISHI MONTERO service

GDI -Troubleshooting 13A-34
Code No.P0170 Abnormal fuel systemProbable cause
Range of Check
DEngine: Being learning the air - fuel ratio
Set Conditions
DTen seconds or more havebeenpassed while the fuel injection amount
compensation value is too low.
or
DTen seconds or more havebeenpassed while the fuel injection amount
compensation value is too high.DMalfunction of fuel supply system
DMalfunction of oxygen sensor (front)
DMalfunction of intake air temperature sensor
DMalfunction of barometric pressure sensor
DMalfunction of air flow sensor
DMalfunction of engine-ECU
Repair
OK
MUT-
IIData list
74 Fuel pressure sensor (Refer to
13A-105, DATA LIST
REFERENCE TABLE.)NGCheck fuel leakage around the fuel
pump (high-pressure) line.NG
NO
Check the air intake from the intake
hose and intake manifold.NG
Repair
OK
Check the oxygen sensor (front)
(Refer to P.13A-230.)NG
Replace
MUT-
IISelf-Diag Code
Is any diagnosis code other than
No.P0170 output?YESRefer to P.13A-15, INSPECTION
CHART FOR DIAGNOSIS CODES.
OK
Check the exhaust gas leaks from
the exhaust manifold.NG
Repair
OK
Check the throttle body (around the
throttle valve), and clean if
necessary. (Refer to P.13A-220).NG
Cleaning
OK
MUT-
IIData list
11 Oxygen sensor (front)
12 Air flow sensor
13 Intake air temperature sensor
21 Engine coolant temperature
sensor
25 Barometric pressure sensor
(Refer to 13A-105, DATA LIST
REFERENCE TABLE.)
Reference
If all the service data is normal, go
to “OK.”
If any abnormal service is found, go
to “NG.”NGRefer to the Inspection procedure for
the sensor, which is indicated by the
abnormal service data.
(Refer to P.13A-15, INSPECTION
CHART FOR DIAGNOSIS CODES.)OK
Replace the fuel pump
(high-pressure).
Check the purge control solenoid
valve (Refer to GROUP 17 -
Emission Control).NG
Replace
OK
To the nextpageOK


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GDI -Troubleshooting GDI -Troubleshooting 13A-55
Code No.P0301 No.1 cylinder misfire detected.
Code No.P0302 No.2 cylinder misfire detected.
Code No.P0303 No.3 cylinder misfire detected.
Code No.P0304 No.4 cylinder misfire detected.
Code No.P0305 No.5 cylinder misfire detected.Probable cause
Range of Check
DThe enginespeed is 500 - 4,500 r/min.
DWhile the engine is runningexcept deceleration and sudden acceleration.
Set Conditions
DThe number of misfires exceeds a predetermined number per 200engine
revolutions (Misfire has occurred in only one cylinder).
or
DThe number of misfires exceeds a predetermined number per 100engine
revolutions (Misfire has occurred in only one cylinder).DMalfunction of the ignition system
DAbnormal compression
DMalfunction of injector
DMalfunction of engine-ECU
NG
Check the harness wire between the
ignition coil and the engine-ECU.
NG
Replace
NG
Repair
(2) NG
OK
Check the ignition failure sensor
(Refer to GROUP 16 - Ignition
System.)
OK
Check the harness wire between the
ignition coil and the earth, and repair
if necessary. (3) NG
OK
Measure at ignition coil connectors
B-101, B-108, B-112, B-113, B-116,
B-119.
DDisconnect the connector and
measure at the harness side.
(1) The voltage between terminal 1
and earth
(Ignition switch: ON)
OK:
System voltage
(2) The voltage between terminal 3
and earth
(Engine: cranking)
OK:
0.5 - 4.0 V
(3) The resistance between terminal
2 and earth
OK:
2Wor less(1) NGCheck the following connectors:
B-04, B-107, D-208, D-223NG
Repair
Check the ignition coil (Refer to
GROUP 16 - Ignition System.)
Check the compression pressure.
(Refer to GROUP 11A - On-vehicle
Service.)Repair
Replace the engine-ECU.
OK
Check the harness wire between the
ignition coil and the ignition failure
sensor, and between the ignition coil
and the ignition failure sensor.
NG
Repair
OK
NGNG
Repair
OKReplace
NG
Check the spark plugs.
Check the trouble symptoms.
OK
Check the trouble symptoms.NGReplace the engine-ECU.
Check the following connectors:
B-101, B-108, B-112, B-113, B-116,
B-119
Check the following connector:
B-107, D-116
OK


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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-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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GDI -Troubleshooting 13A-127
METHOD OF READING AND ERASING DIAGNOSIS
CODES
Refer to GROUP 00 - How to Use Troubleshooting/Inspection
Service Points.
DIAGNOSIS USING DIAGNOSIS 2 MODE
1. Switch the diagnosis mode of the engine-A/T-ECU to
DIAGNOSIS 2 mode using the MUT-II, and then carry
out a road test.
2. Take a reading of the diagnosis code and repair the
problem location.
3. Turn the ignition switch to the LOCK (OFF) position, and
then back to ON again.
NOTE
By turning the ignition switch to the LOCK (OFF) position,
the engine-A/T-ECU will switch the DIAGNOSIS 2 mode
to DIAGNOSIS 1 mode.
4. Erase the diagnosis codes.
INSPECTION USING MUT-II
DATA LIST AND
ACTUATOR TESTING
1. Carry out inspection by means of the data list and actuator
test function. If there is an abnormality, check and repair
the chassis harnesses and components.
2. After repairing, re-check using the MUT-IIand check that
the abnormal input and output have returned to normal
as a result of the repairs.
3. Erase the diagnosis code memory.
4. Remove the MUT-II, and then start the engine again and
carry out a road test to confirm that the problem has
disappeared.


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GDI -Troubleshooting 13A-160
Code No.89 Abnormal fuel systemProbable cause
Range of Check
DEngine: Being learning the air - fuel ratio
Set Conditions
DTen seconds or more havebeenpassed while the fuel injection amount
compensation value is too low.
or
DTen seconds or more havebeenpassed while the fuel injection amount
compensation value is too high.DMalfunction of fuel supply system
DMalfunction of oxygen sensor
DMalfunction of intake air temperature sensor
DMalfunction of barometric pressure sensor
DMalfunction of air flow sensor
DMalfunction of engine-A/T-ECU
Repair
OK
MUT-
IIData list
74 Fuel pressure sensor (Refer to
13A-198, DATA LIST
REFERENCE TABLE.)NGCheck fuel leakage around the fuel
pump (high-pressure) line.NG
NO
Check the air intake from the intake
hose and right bank intake manifold.NG
Repair
OK
Check the oxygen sensor (Refer to
P.13A-230.)NG
Replace
MUT-
IISelf-Diag Code
Is any diagnosis code other than
No.89 output?YESRefer to P.13A-130, INSPECTION
CHART FOR DIAGNOSIS CODES.
OK
Check the exhaust gas leaks from
the right bank exhaust manifold.NG
Cleaning
OK
Check the throttle body (around the
throttle valve), and clean if
necessary. (Refer to P.13A-220).NG
Cleaning
OK
MUT-
IIData list
11 Oxygen sensor
12 Air flow sensor
13 Intake air temperature sensor
21 Engine coolant temperature
sensor
25 Barometric pressure sensor
(Refer to 13A-198, DATA LIST
REFERENCE TABLE.)
Reference
If all the service data is normal, go
to “OK.”
If any abnormal service is found, go
to “NG.”NGRefer to the Inspection procedure for
the sensor, which is indicated by the
abnormal service data.
(Refer to P.13A-130, INSPECTION
CHART FOR DIAGNOSIS CODES.)OK
Replace the fuel pump
(high-pressure).
Check the purge control solenoid
valve (Refer to GROUP 17 -
Emission Control).NG
Replace
OK
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GDI -Troubleshooting 13A-191
Inspection procedure 27
Ignition switch-ST and inhibitor switch system
Probable cause
The ignition switch-ST inputs a HIGH signal to the engine-A/T-ECU while the
engine iscranking. The engine-A/T-ECU controls fuel injection, etc. during
starting based on this input.
The inhibitor switch inputs the position of the selector lever to the
engine-A/T-ECU. The engine-A/T-ECU uses this signal to carry outidlespeed
control.DMalfunction of the ignition switch
DMalfunction of the inhibitor switch
DOpen circuit or short-circuited harness wire
between the ignition switch and the inhibitor
switch, or improper connector contact.
DMalfunction of the engine-A/T-ECU
OK
Check the following connector:
D-120
OK
Ignition switch check
(Refer to GROUP 54 - Ignition Switch.)
OK
Check the trouble symptoms.
OK
Check the trouble symptoms.
MUT-
IIData list
Confirm the data list concerning the A/T system.
61 Inhibitor switch
(Refer to GROUP 23 - Troubleshooting.)NGCheck the inhibitor switch system.
(Refer to GROUP 23 - Troubleshooting.)
OK
Measure at engine-A/T-ECU connector D-120.
DDisconnect the connector, and measure at the harness
side.
DThe voltage between terminal 58 and earth
(Selector lever position: P or N)
(Ignition switch: START)
OK:
System voltageNGCheck the following connector:
C-05
NG
Repair
NG
Check the harness between the inhibitor switch and the
ignition switch.
OK
Check the trouble symptoms.
NG
Repair
OK
Check the inhibitor switch.
DThe continuity between terminals 9 and 10 (Refer to
GROUP 23 - On-vehicle Service.)NGReplace
NG
Replace the engine-A/T-ECU.
NG
Repair
NG
Check the harness wire between the inhibitor switch and the
engine-A/T-ECU, and repair if necessary.
OK
Measure at inhibitor switch connector C-05.
DDisconnect the connector, and measure at the harness
side.
DThe voltage between terminal 10 and earth (Ignition switch:
ON)
OK:
System voltageNGCheck the following connector:
E-114
NG
Repair


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GDI -Troubleshooting 13A-194
Inspection procedure 30
Power steering fluid pressure switch system
Probable cause
The presence or absence of power steeringload is input to the engine-A/T-ECU.
Based on this signal, the engine-A/T-ECU controls the throttle control servo so
that idlespeed increases when the power steering is in operation.DMalfunction of the power steering fluid pressure
switch.
DImproper connector contact,opencircuit or
short-circuited harness wire
DMalfunction of the engine-A/T-ECU
OK
Measure at power steering fluid
pressure switch connector B-51.
DDisconnect the connector, and
measure at the harness side.
DThe voltage between terminal 1
and earth
(Ignition switch: ON)
OK:
System voltageNGCheck the following connector:
D-120NG
Repair
OK
Check the trouble symptoms.
NG
Check the harness wire between the
engine-A/T-ECU and the power
steering fluid pressure switch, and
repair if necessary.OK
Check the following connector:
B-51NG
Repair
OK
Check the trouble symptoms.NGReplace the engine-A/T-ECU.
Check the power steering fluid
pressure switch (Refer to GROUP
37A - On-vehicle Service.)NG
Replace
Inspection procedure 31
A/C switch and A/C relay system
Probable cause
When an A/C ON signal is input to the engine-A/T-ECU, the engine-A/T-ECU
controls the throttle control servo so thatidlespeed increases, and also operates
the A/C compressor magnetic clutch.DMalfunction of the A/C control system
DMalfunction of the A/C switch
DImproper connector contact,opencircuit or
short-circuited harness wire
DMalfunction of the engine-A/T-ECU
Service the A/C compressor relay.
(Refer to GROUP 55 - On-vehicle
Service.)NG
Replace
OK
Measure at engine-A/T-ECU
connectors D-119, D-121.
DDisconnect the connector, and
measure at the harness side.
DThe voltage between terminal 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-119, D-121NG
Repair
OK
Check the trouble symptoms.
NG
Replace the engine-A/T-ECU.
NG
Check the A/C system (Refer to
GROUP 55 - Troubleshooting.)


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