2006 INFINITI QX56 fuel

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-69
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Revision: November 2009 2006 QX56
RELATIONSHIP BETWEEN MIL, DTC, 1ST TRIP DTC AND DRIVING PATTERNS EXCEPT FOR
“MISFIRE ”, “FUEL INJECTION SYSTEM”
*1: When the same malfunction is
detected in two consecutive trips,
MIL will light up. *2: MIL will go off after vehicle is driven
3 times (pattern B) without any mal-
functions. *3: When the same malfunction is
detected in two consecutive trips, the
DTC and the freeze frame data will
be stored in ECM.
*4: The DTC and the freeze frame data will not be displayed any longer after
vehicle is driven 40 times (pattern A)
without the same malfunction.
(The DTC and the freeze frame data
still remain in ECM.) *5: When a malfunction is detected for
the first time, the 1st trip DTC and
the 1st trip freeze frame data will be
stored in ECM. *6: 1st trip DTC will be cleared after
vehicle is driven once (pattern B)
without the same malfunction.
*7: When the same malfunction is detected in the 2nd trip, the 1st trip
freeze frame data will be cleared.
SEF393SD

EC-70Revision: November 2009
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2006 QX56
EXPLANATION FOR DRIVING PATTERNS EXCEPT FOR “MISFIRE DETERIORATION>”, “FUEL INJECTION SYSTEM”


The A counter will be cleared when the malfunction is detected regardless of (1) - (4).

The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.

The DTC will not be displayed after the A counter reaches 40.

Driving pattern B means the vehicle operation as follows:
All components and systems should be monitored at least once by the OBD system.

The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.

The B counter will be counted up when driving pattern B is satisfied without any malfunctions.

The MIL will go off when the B counter reaches 3 (*2 in OBD SYSTEM OPERATION CHART).
AEC574

EC-80Revision: November 2009
BASIC SERVICE PROCEDURE
2006 QX56
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within thespecifications.
13. If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried out successfully. In this case, find the cause of the incident by referring to the DIAGNOSTIC PROCE-
DURE below.
DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:
1.Check that throttle valve is fully closed.
2. Check PCV valve operation.
3. Check that downstream of throttle valve is free from air leakage.
4. When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and eliminate the cause of the incident.
It is useful to perform EC-134, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
5. If any of the following conditions occur after the engine has started, eliminate the cause of the
incident and perform Idle Air Volume Learning all over again:

Engine stalls.

Erroneous idle.
Fuel Pressure CheckUBS00L01
FUEL PRESSURE RELEASE
With CONSULT-II
1. Turn ignition switch ON.
2. Perform “FUEL PRESSURE RELEASE ” in “WORK SUPPORT ”
mode with CONSULT-II.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5 ° BTDC (in P or N position)
SEC897C
SEF214Y

BASIC SERVICE PROCEDUREEC-81
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Revision: November 2009 2006 QX56
Without CONSULT-II
1. Remove fuel pump fuse located in IPDM E/R.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch OFF.
5. Reinstall fuel pump fuse after servicing fuel system.
BBIA0380E

EC-82Revision: November 2009
BASIC SERVICE PROCEDURE
2006 QX56
FUEL PRESSURE CHECK
CAUTION:

Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.

Be careful not to scratch or get the fuel hose connection area dirty when servicing, so that the
quick connector o-ring maintains sealability.

Use Fuel Pressure Gauge Kit J-44321 and Fuel Pressure Adapter J-44321-6 to check fuel pressure.

Do not perform fuel pressure check with electrical system operating (i.e. lights, rear defog, A/C,
etc.). Fuel pressure gauge may indicate false readings due to varying engine loads and changes in
manifold vacuum.
NOTE:
Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel pres-
sure cannot be completely released because JA60 models do not have fuel return system.
1. Release fuel pressure to zero. Refer to EC-80, "
FUEL PRESSURE RELEASE" .
2. Remove engine cover.
3. Remove fuel hose using Quick Connector Release J-45488. Refer to EM-17, "
INTAKE MANIFOLD" .

Do not twist or kink fuel hose because it is plastic hose.

Do not remove fuel hose from quick connector.

Keep fuel hose connections clean.
4. Install Fuel Pressure Adapter J-44321-6 and Fuel Pressure Gauge (from kit J-44321) as shown in figure.

Do not distort or bend fuel rail tube when installing fuel pres-
sure gauge adapter.

When reconnecting fuel hose, check the original fuel hose for
damage and abnormality.
5. Turn ignition switch ON (reactivate fuel pump), and check for fuel leakage.
6. Start engine and check for fuel leakage.
7. Read the indication of fuel pressure gauge.

During fuel pressure check, check for fuel leakage from fuel
connection every 3 minutes.
8. If result is unsatisfactory, go to next step.
9. Check the following.

Fuel hoses and fuel tubes for clogging

Fuel filter for clogging

Fuel pump

Fuel pressure regulator for clogging
If OK, replace fuel pressure regulator.
If NG, repair or replace.
10. Before disconnecting Fuel Pressure Gauge and Fuel Pressure Adapter J-44321-6, release fuel pressure to zero. Refer to EC-80, "
FUEL PRESSURE RELEASE" .
At idling:
Approximately 350 kPa (3.57 kg/cm
2 , 51 psi)
BBIA0390E

TROUBLE DIAGNOSISEC-83
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Revision: November 2009 2006 QX56
TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionUBS00L02
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on EC-84, "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Diagnostic Worksheet like the example
on EC-88, "
Worksheet Sample" should be used.
Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
MEF036D
SEF233G
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EC-86Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
5. PERFORM DTC CONFIRMATION PROCEDURE
Perform DTC Confirmation Procedure for the displayed DTC* , and then make sure that DTC*
1 is detected
again.
At this time, always connect CONSULT-II to the vehicle, and check diagnostic results in real time on “DATA
MONITOR (AUTO TRIG) ”.
If two or more DTCs*
1 are detected, refer to EC-89, "DTC Inspection Priority Chart" and determine trouble
diagnosis order.
NOTE:

Freeze frame data*2 is useful if the DTC*1 is not detected.

Perform Overall Function Check if DTC Confirmation Procedure is not included on Service Manual. This
simplified check procedure is an effective alternative though DTC*
1 cannot be detected during this check.
If the result of Overall Function Check is NG, it is the same as the detection of DTC*
1 by DTC Confirma-
tion Procedure.
Is DTC*
1 detected?
Yes >> GO TO 10.
No >> Check according to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
6. PERFORM BASIC INSPECTION
Perform EC-71, "
Basic Inspection" .
With CONSULT-II>>GO TO 7.
Without CONSULT-II>>GO TO 9.
7. PERFORM DATA MONITOR (SPEC) MODE
With CONSULT-II
Make sure that “MAS A/F SE-B1 ”, “B/FUEL SCHDL ”, and “A/F
ALPHA-B1 ”, “A/F ALPHA-B2 ” are within the SP value using CON-
SULT-II “DATA MONITOR (SPEC) ” mode. Refer to EC-134, "
TROU-
BLE DIAGNOSIS - SPECIFICATION VALUE" .
Are they within the SP value?
Yes >> GO TO 9.
No >> GO TO 8.
8. DETECT MALFUNCTIONING PART BY TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Detect malfunctioning part according to EC-135, "
Diagnostic Procedure" .
Is malfunctioning part detected?
Yes >> GO TO 11.
No >> GO TO 9.
9. DETECT MALFUNCTIONING SYSTEM BY SYMPTOM MATRIX CHART
Detect malfunctioning system according to EC-92, "
Symptom Matrix Chart" based on the confirmed symptom
in step 4, and determine the trouble diagnosis order based on possible causes and symptom.
>> GO TO 10.
SEF601Z

TROUBLE DIAGNOSISEC-87
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Revision: November 2009 2006 QX56
10. DETECT MALFUNCTIONING PART BY DIAGNOSTIC PROCEDURE
Inspect according to Diagnostic Procedure of the system.
NOTE:
The Diagnostic Procedure in EC section described based on open circuit inspection. A short circuit inspection
is also required for the circuit check in the Diagnostic Procedure. For details, refer to Circuit Inspection in GI-
28, "How to Perform Efficient Diagnosis for an Electrical Incident" .
Is malfunctioning part detected?
Ye s > > G O T O 11 .
No >> Monitor input data from related sensors or check voltage of related ECM terminals using CON- SULT-II. Refer to EC-105, "
ECM Terminals and Reference Value" , EC-129, "CONSULT-II Refer-
ence Value in Data Monitor" .
11 . REPAIR OR REPLACE THE MALFUNCTIONING PART
1. Repair or replace the malfunctioning part.
2. Reconnect parts or connectors disconnected during Diagnostic Procedure again after repair and replace- ment.
3. Check DTC. If DTC is displayed, erase it, refer to EC-61, "
HOW TO ERASE EMISSION-RELATED DIAG-
NOSTIC INFORMATION" .
>> GO TO 12.
12. FINAL CHECK
When DTC was detected in step 2, perform DTC Confirmation Procedure or Overall Function Check again,
and then make sure that the malfunction have been repaired securely.
When symptom was described from the customer, refer to confirmed symptom in step 3 or 4, and make sure
that the symptom is not detected.
OK or NG
NG (DTC*1 is detected)>>GO TO 10.
NG (Symptom remains)>>GO TO 6.
OK >> 1. Before returning the vehicle to the customer, make sure to erase unnecessary DTC*
1 in ECM
and TCM (Transmission Control Module). (Refer to EC-61, "
HOW TO ERASE EMISSION-
RELATED DIAGNOSTIC INFORMATION" and AT- 3 8 , "OBD-II Diagnostic Trouble Code
(DTC)" .)
2. If the completion of SRT is needed, drive vehicle under the specific driving pattern. Refer to EC-
58, "Driving Pattern" .
3. INSPECTION END
*1: Include 1st trip DTC.
*2: Include 1st trip freeze frame data.
DIAGNOSTIC WORKSHEET
Description
There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about a incident. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MIL to come on steady or blink and
DTC to be detected. Examples:

Vehicle ran out of fuel, which caused the engine to misfire.

Fuel filler cap was left off or incorrectly screwed on, allowing fuel
to evaporate into the atmosphere.
SEF907L