check engine INFINITI QX4 2005 Factory Service Manual

EC-64Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
–Test values
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
Malfunction Indicator Lamp (MIL)UBS00KZS
DESCRIPTION
The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON with-
out the engine running. This is a bulb check.
If the MIL does not light up, refer to DI-30, "
WARNING LAMPS" ,
or see EC-667, "
MIL AND DATA LINK CONNECTOR" .
2. When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction.
ON BOARD DIAGNOSTIC SYSTEM FUNCTION
The on board diagnostic system has the following three functions.
When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when there is
malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means
of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands the
driver to repair the malfunction.
SEF 2 17 U
Diagnostic Test
ModeKEY and ENG.
Statu sFunction Explanation of Function
Mode I Ignition switch in
ON position
Engine stoppedBULB CHECK This function checks the MIL bulb for damage (blown,
open circuit, etc.).
If the MIL does not come on, check MIL circuit.
Engine running MALFUNCTION
WARNINGThis is a usual driving condition. When a malfunction is
detected twice in two consecutive driving cycles (two trip
detection logic), the MIL will light up to inform the driver
that a malfunction has been detected.
The following malfunctions will light up or blink the MIL in
the 1st trip.

Misfire (Possible three way catalyst damage)

One trip detection diagnoses
Mode II Ignition switch in
ON position
Engine stoppedSELF-DIAGNOSTIC
RESULTSThis function allows DTCs and 1st trip DTCs to be read.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut

EC-72Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
BASIC SERVICE PROCEDUREPFP:00018
Basic InspectionUBS00KZU
1. INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for
scheduled maintenance.
2. Open engine hood and check the following:
–Harness connectors for improper connections
–Wiring harness for improper connections, pinches and cut
–Vacuum hoses for splits, kinks and improper connections
–Hoses and ducts for leaks
–Air cleaner clogging
–Gasket
3. Confirm that electrical or mechanical loads are not applied.
–Headlamp switch is OFF.
–Air conditioner switch is OFF.
–Rear window defogger switch is OFF.
–Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature
indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no
load.
6. Make sure that no DTC is displayed with CONSULT-II or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
SEF 9 83 U
SEF 9 76 U
SEF 9 77 U

BASIC SERVICE PROCEDURE
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3. CHECK TARGET IDLE SPEED
With CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no
load, then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no load, then run engine at idle speed for about
1 minute.
3. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 4.
4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-90, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
PBIA8513J
650 ± 50 rpm (in P or N position)
SEF 0 58 Y
650 ± 50 rpm (in P or N position)

EC-74Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
6. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-91, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 7.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
7. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.

Check camshaft position sensor (PHASE) and circuit. Refer to EC-291, "DTC P0340 CMP SENSOR
(PHASE)" .

Check crankshaft position sensor (POS) and circuit. Refer to EC-284, "DTC P0335 CKP SENSOR (POS)"
.
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace.
2. GO TO 4.
9. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
>> GO TO 4. 650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)

BASIC SERVICE PROCEDURE
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10. CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-77, "
IGNITION TIMING" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 11.
11 . PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-90, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-91, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 14.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
14. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.15 ± 5° BTDC (in P or N position)
BBIA0379E
650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)

EC-76Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
15. CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-77, "
IGNITION TIMING" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 16.
16. CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-35, "
TIMING CHAIN" .
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation.
2. GO TO 4.
17. DETECT MALFUNCTIONING PART
Check the following.

Check camshaft position sensor (PHASE) and circuit. Refer to EC-291, "DTC P0340 CMP SENSOR
(PHASE)" .

Check crankshaft position sensor (POS) and circuit. Refer to EC-284, "DTC P0335 CKP SENSOR (POS)"
.
OK or NG
OK >> GO TO 18.
NG >> 1. Repair or replace.
2. GO TO 4.
18. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
>> GO TO 4.
19. INSPECTION END
Did you replace ECM, referring this Basic Inspection procedure?
Ye s o r N o
Ye s > > 1 . P e r f o r m EC-90, "VIN Registration" .
2.INSPECTION END
No >>INSPECTION END 15 ± 5° BTDC (in P or N position)
BBIA0379E

BASIC SERVICE PROCEDURE
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Idle Mixture Ratio AdjustmentUBS00KZW
PREPARATION
1. Make sure that the following parts are in good order.

Battery

Ignition system

Engine oil and coolant levels

Fuses

ECM harness connector

Vacuum hoses

Air intake system
(Oil filler cap, oil level gauge, etc.)

Fuel pressure

Engine compression

Throttle valve

Evaporative emission system
2. On air conditioner equipped models, checks should be carried out while the air conditioner is OFF.
3. Checks should be carried out while selector lever is in P or N position.
4. When measuring CO percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5. Turn off headlamp, heater blower, rear window defogger.
6. Keep front wheels pointed straight ahead.

BASIC SERVICE PROCEDURE
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Revision: October 20052005 QX56
DETAILED PROCEDURE
1. INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for
scheduled maintenance.
2. Open engine hood and check the following:
–Harness connectors for improper connections
–Wiring harness for improper connections, pinches and cut
–Vacuum hoses for splits, kinks and improper connections
–Hoses and ducts for leaks
–Air cleaner clogging
–Gasket
3. Confirm that electrical or mechanical loads are not applied.
–Head lamp switch is OFF.
–Air conditioner switch is OFF.
–Rear window defogger switch is OFF.
–Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature
indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no
load.
6. Make sure that no DTC is displayed with CONSULT-II or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
SEF 9 83 U
SEF 9 76 U
SEF 9 77 U

EC-82Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
3. CHECK TARGET IDLE SPEED
With CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) 2 or 3 times under no load,
then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) 2 or 3 times under no load, then run engine at idle speed for about 1
minute.
3. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 4.
4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-90, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
PBIA8513J
650 ± 50 rpm (in P or N position)
SEF 0 58 Y
650 ± 50 rpm (in P or N position)

BASIC SERVICE PROCEDURE
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6. PERFORM IDLE AIR VOLUME LEARNING
Perform EC-91, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 7.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
7. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.

Check camshaft position sensor (PHASE) and circuit. Refer to EC-291, "DTC P0340 CMP SENSOR
(PHASE)" .

Check crankshaft position sensor (POS) and circuit. Refer to EC-284, "DTC P0335 CKP SENSOR (POS)"
.
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace.
2. GO TO 4.
9. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
>> GO TO 4. 650± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)