stop start INFINITI QX4 2005 Factory Workshop Manual

TROUBLE DIAGNOSIS
EC-141
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Revision: October 20052005 QX56
CONSULT-II Reference Value in Data MonitorUBS00L0D
Remarks:

Specification data are reference values.

Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly related to their components signals/values/operations.
i.e. Adjust ignition timing with a timing light before monitoring IGN TIMING, because the monitor may show the specification data in
spite of the ignition timing not being adjusted to the specification data. This IGN TIMING monitors the data calculated by the ECM
according to the signals input from the camshaft position sensor and other ignition timing related sensors.
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED

Run engine and compare CONSULT-II value with the tachometer indica-
tion.Almost the same speed as the
tachometer indication.
MAS A/F SE-B1 See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
B/FUEL SCHDL See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
A/F ALPHA-B1
A/F ALPHA-B2See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
COOLAN TEMP/S

Engine: After warming up More than 70°C (158°F)
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming upMaintaining engine speed at 2,000
rpmFluctuates around 1.5 V
HO2S2 (B1)
HO2S2 (B2)

Warm-up condition

After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no loadRevving engine from idle to 3,000 rpm
quickly0 - 0.3V ←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)

Warm-up condition

After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load.Revving engine from idle to 3,000 rpm
quickly.LEAN ←→ RICH
VHCL SPEED SE

Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
BATTERY VOLT

Ignition switch: ON (Engine stopped) 11 - 14V
ACCEL SEN 1

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
ACCEL SEN 2*

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
THRTL SEN 1
THRTL SEN 2*

Ignition switch: ON
(Engine stopped)

Selector lever: DAccelerator pedal: Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
EVAP SYS PRES

Ignition switch: ON Approx. 1.8 - 4.8V
START SIGNAL

Ignition switch: ON → START → ON OFF → ON → OFF
CLSD THL POS

Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
AIR COND SIG

Engine: After warming up, idle
the engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
P/N POSI SW

Ignition switch: ONSelector lever: P or N ON
Selector lever: Except above OFF
PW/ST SIGNAL

Engine: After warming up, idle
the engineSteering wheel: Not being turned
(Forward direction)OFF
Steering wheel: Being turned ON
LOAD SIGNAL

Ignition switch: ONRear window defogger switch is ON
and/or lighting switch is in 2nd.ON
Rear window defogger switch is OFF
and lighting switch is OFF.OFF

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-149
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DETAILED PROCEDURE
1. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Confirm that the testing conditions are met. Refer to EC-146, "
Testing Condition" .
3. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR
(SPEC)” mode, and make sure that the each indication is within
the SP value.
NOTE:
Check “A/F ALPHA-B1”, “A/F ALPHA-B2” for approximately 1
minute because they may fluctuate. It is NG if the indication is
out of the SP value even a little.
OK or NG
OK >> GO TO 17.
NG (Less than the SP value)>>GO TO 2.
NG (More than the SP value)>>GO TO 3.
2. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 4.
NG (More than the SP value)>>GO TO 19.
3. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 6.
NG (More than the SP value)>>GO TO 6.
NG (Less than the SP value)>>GO TO 25.
4. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Stop the engine.
2. Disconnect PCV hose, and then plug it.
3. Start engine.
4. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> GO TO 5.
NG >> GO TO 6.
PBIB2369E
PBIB2332E
PBIB2332E

EC-150Revision: October 2005
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2005 QX56
5. CHANGE ENGINE OIL
1. Stop the engine.
2. Change engine oil.
NOTE:
This symptom may occur when a large amount of gasoline is mixed with engine oil because of driving
conditions (such as when engine oil temperature does not rise enough since a journey distance is too
short during winter). The symptom will not be detected after changing engine oil or changing driving con-
dition.
>>INSPECTION END
6. CHECK FUEL PRESSURE
Check fuel pressure. (Refer to EC-94, "
FUEL PRESSURE CHECK" .)
OK or NG
OK >> GO TO 9.
NG (Fuel pressure is too high)>>Replace fuel pressure regulator, refer to EC-94, "
FUEL PRESSURE
CHECK" . GO TO 8.
NG (Fuel pressure is too low)>>GO TO 7.
7. DETECT MALFUNCTIONING PART
1. Check the following.
–Clogged and bent fuel hose and fuel tube
–Clogged fuel filter
–Fuel pump and its circuit (Refer to EC-637, "FUEL PUMP CIRCUIT" .)
2. If NG, repair or replace the malfunctioning part. (Refer to EC-94, "
FUEL PRESSURE CHECK" .)
If OK, replace fuel pressure regulator.
>> GO TO 8.
8. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 9.
9. PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine
speed drop.
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
PBIB0133E

EC-152Revision: October 2005
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2005 QX56
15. DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
16. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> Detect malfunctioning part according to EC-104, "
Symptom Matrix Chart" .
17. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG (More than the SP value)>>GO TO 18.
NG (Less than the SP value)>>GO TO 25.
18. DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
–Engine oil level is too high
–Engine oil viscosity
–Belt tension of power steering, alternator, A/C compressor, etc. is excessive
–Noise from engine
–Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
–Valve clearance malfunction
–Intake valve timing control function malfunction
–Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19. CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system
OK or NG
OK >> GO TO 21.
NG >> Repair or replace malfunctioning part, and then GO TO 20.
PBIB2332E

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-153
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Revision: October 20052005 QX56
20. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG (“B/FUEL SCHDL” is more, “A/F ALPHA-B1”, “A/F ALPHA-B2” are less than the SP value)>>GO TO 21.
21. DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and
then reconnect it again.
>> GO TO 22.
22. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> 1. Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-183, "DTC
P0102, P0103 MAF SENSOR" .
2. GO TO 29.
NG >> GO TO 23.
23. CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 24.
NG (More than the SP value)>>Replace mass air flow sensor, and
then GO TO 29.
24. REPLACE ECM
1. Replace ECM.
2. Perform initialization of NVIS(NATS) system and registration of all NVIS(NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
3. Perform EC-90, "
VIN Registration" .
4. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
5. Perform EC-90, "
Throttle Valve Closed Position Learning" .
6. Perform EC-91, "
Idle Air Volume Learning" .
>> GO TO 29.
PBIB2370E

DTC P0101 MAF SENSOR
EC-175
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Revision: October 20052005 QX56
DTC Confirmation ProcedureUBS00H0Y
Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A
NOTE:
If engine will not start or stops soon, wait at least 10 seconds with engine stopped (Ignition switch ON) instead
of running engine at idle speed.
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and warm it up to normal operating temperature.
4. Run engine for at least 10 seconds at idle speed.
5. If 1st trip DTC is detected, go to EC-178, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION B
CAUTION:
Always drive vehicle at a safe speed.
With CONSULT-II
1. Turn ignition switch ON.
2. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to EC-178, "
Diagnostic Procedure" .
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Check the voltage of “MAS A/F SE-B1” with “DATA MONITOR”.
5. Increases engine speed to about 4,000 rpm.
6. Monitor the linear voltage rise in response to engine speed
increases.
If NG, go to EC-178, "
Diagnostic Procedure" .
If OK, go to following step.
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DTC P0101 MAF SENSOR
EC-181
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Revision: October 20052005 QX56
Component InspectionUBS00H12
MASS AIR FLOW SENSOR
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-II and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check indication under the follow-
ing conditions.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
5. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system parts
b. If NG, repair or replace malfunctioning part and perform step 2 to 4 again.
If OK, go to next step.
6. Turn ignition switch OFF.
7. Disconnect mass air flow sensor harness connector and reconnect it again.
8. Perform step 2 to 4 again.
9. If NG, clean or replace mass air flow sensor.
Without CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 51 (Mass air flow sensor
signal) and ground.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
4. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system parts
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.)1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.3 to Approx. 2.4
PBIB2371E
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.)1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.3 to Approx. 2.4
PBIB11 06 E

DTC P0102, P0103 MAF SENSOR
EC-189
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Revision: October 20052005 QX56
Component InspectionUBS00H1A
MASS AIR FLOW SENSOR
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-II and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check indication under the follow-
ing conditions.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
5. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system parts
b. If NG, repair or replace malfunctioning part and perform step 2 to 4 again.
If OK, go to next step.
6. Turn ignition switch OFF.
7. Disconnect mass air flow sensor harness connector and reconnect it again.
8. Perform step 2 to 4 again.
9. If NG, clean or replace mass air flow sensor.
Without CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 51 (Mass air flow sensor
signal) and ground.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
4. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system parts
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.)1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.3 to Approx. 2.4
PBIB2371E
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.)1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.3 to Approx. 2.4
PBIB11 06 E

DTC P0125 ECT SENSOR
EC-209
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Revision: October 20052005 QX56
DTC Confirmation ProcedureUBS00H20
CAUTION:
Be careful not to overheat engine.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Check that “COOLAN TEMP/S” is above 10°C (50°F).
If it is above 10°C (50°F), the test result will be OK.
If it is below 10°C (50°F), go to following step.
4. Start engine and run it for 65 minutes at idle speed.
If “COOLAN TEMP/S” increases to more than 10°C (50°F)
within 65 minutes, stop engine because the test result will
be OK.
5. If 1st trip DTC is detected, go to EC-209, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00H21
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-210, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace engine coolant temperature sensor.
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BBIA0354E

EC-232Revision: October 2005
DTC P0139, P0159 HO2S2
2005 QX56
2. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode
with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector, and restart
and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con-
nector.
5. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-236, "DTC
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION" or EC-245, "DTC P0172, P0175 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 3.
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BBIA0368E