2007 INFINITI QX56 engine

BASIC SERVICE PROCEDURE
EC-79
< SERVICE INFORMATION >
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7. Make sure that “CMPLT” is displayed on CONSULT-II screen. If
“CMPLT” is not displayed, Idle Air Volume Learning will not be
carried out successfully. In this case, find the cause of the inci-
dent by referring to the DIAGNOSTIC PROCEDURE below.
8. Rev up the engine two or three times and make sure that idle
speed and ignition timing are within the specifications.
Without CONSULT-II
NOTE:
•It is better to count the time accurately with a clock.
•It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit has
a malfunction.
1. Perform EC-77, "
Accelerator Pedal Released Position Learning" .
2. Perform EC-77, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
7. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops
blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MIL turned ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.
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.
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5° BTDC (in P or N position)
MBIB0238E
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5° BTDC (in P or N position)
SEC897C

EC-80
< SERVICE INFORMATION >
BASIC SERVICE PROCEDURE
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-129
.
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 CheckINFOID:0000000003531616
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.
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.
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 mani-
fold 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 "FUEL PRESSURE RELEASE" .
2. Remove engine cover.
3. Remove fuel hose using Quick Connector Release J-45488. Refer to EM-17
.
• 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.
SEF214Y
BBIA0380E

BASIC SERVICE PROCEDURE
EC-81
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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 "FUEL PRESSURE RELEASE" .At idling:
Approximately 350 kPa (3.57 kg/cm
2 , 51 psi)
BBIA0390E

EC-82
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
Trouble Diagnosis IntroductionINFOID:0000000003531617
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 "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 "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.
WORK FLOW
MEF036D
SEF233G
SEF234G

EC-86
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
2. If the completion of SRT is needed, drive vehicle under the specific driving pattern. Refer to
EC-49, "
Emission-related Diagnostic Information" .
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

EC-88
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Fail-Safe Chart
INFOID:0000000003531619
When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.
Priority Detected items (DTC)
1 • U1000 U1001 CAN communication line
• U1010 CAN communication
• P0101 P0102 P0103 Mass air flow sensor
• P0112 P0113 P0127 Intake air temperature sensor
• P0117 P0118 P0125 Engine coolant temperature sensor
• P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor
• P0128 Thermostat function
• P0181 P0182 P0183 Fuel tank temperature sensor
• P0327 P0328 P0332 P0333 Knock sensor
• P0335 Crankshaft position sensor (POS)
• P0340 Camshaft position sensor (PHASE)
• P0460 P0461 P0462 P0463 Fuel level sensor
• P0500 Vehicle speed sensor
• P0605 ECM
• P0643 Sensor power supply
• P0700 TCM
• P0705 Park/neutral position (PNP) switch
• P0850 Park/neutral position (PNP) switch
• P1550 P1551 P1552 P1553 P1554 Battery current sensor
• P1610 - P1615 NATS
• P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor
2 • P0031 P0032 P0051 P0052 Air fuel ratio (A/F) sensor 1 heater
• P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater
• P0075 P0081 Intake valve timing control solenoid valve
• P0130 P0131 P0132 P0133 P0150 P0151 P0152 P0153 P2A00 P2A03 Air fuel ratio (A/F) sensor 1
• P0137 P0138 P0139 P0157 P0158 P0159 Heated oxygen sensor 2
• P0441 EVAP control system purge flow monitoring
• P0443 P0444 P0445 EVAP canister purge volume control solenoid valve
• P0447 P0448 EVAP canister vent control valve
• P0451 P0452 P0453 EVAP control system pressure sensor
• P0550 Power steering pressure sensor
• P0603 ECM power supply
• P0710 P0717 P0720 P0740 P0744 P0745 P1730 P1752 P1754 P1757 P1759 P1762 P1764 P1767 P1769 P1772
P1774 A/T related sensors, solenoid valves and switches
• P1217 Engine over temperature (OVERHEAT)
• P1140 P1145 Intake valve timing control position sensor
• P1805 Brake switch
• P2100 P2103 P2118 Electric throttle control actuator
• P2101 Electric throttle control function
3 • P0011 P0021 Intake valve timing control
• P0171 P0172 P0174 P0175 Fuel injection system function
• P0300 - P0308 Misfire
• P0420 P0430 Three way catalyst function
• P0442 EVAP control system (SMALL LEAK)
• P0455 EVAP control system (GROSS LEAK)
• P0456 EVAP control system (VERY SMALL LEAK)
• P0506 P0507 Idle speed control system
• P1148 P1168 Closed loop control
• P1211 TCS control unit
• P1212 TCS communication line
• P1421 Cold start control
• P1564 ICC/ASCD steering switch
• P1568 ICC command value
• P1572 ICC/ASCD brake switch
• P1574 ICC/ASCD vehicle speed sensor
• P2119 Electric throttle control actuator

TROUBLE DIAGNOSIS
EC-89
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• 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.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning
ignition switch ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned ON
or START40°C (104°F)
More than approx. 4 minutes after
ignition ON or START80°C (176°F)
Except as shown above40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P0643 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2100
P2103Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2101 Electric throttle control
functionECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2118 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2119 Electric throttle control ac-
tuator(When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the
engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P2122
P2123
P2127
P2128
P2138Accelerator pedal position
sensorThe ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut

EC-90
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Symptom Matrix Chart
INFOID:0000000003531620
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOM
Refer-
ence page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit 11232 22 3 2EC-613
Fuel pressure regulator system 334444444 4EC-80
Injector circuit 11232 22 2EC-608
Evaporative emission system 334444444 4EC-33
Air Positive crankcase ventilation sys-
tem
334444444 41EC-45
Incorrect idle speed adjustment 1 1 1 1 1EC-71
Electric throttle control actuator 112332222 2 2EC-543
,
EC-548
,
EC-554
,
EC-559
IgnitionIncorrect ignition timing adjustment 33111 11 1EC-71
Ignition circuit 11222 22 2EC-626
Main power supply and ground circuit 22333 33 23EC-139
Mass air flow sensor circuit
1
122
222 2EC-186,
EC-194
Engine coolant temperature sensor circuit
333EC-205,
EC-217
Air fuel ratio (A/F) sensor 1 circuitEC-225
,
EC-234
,
EC-242
,
EC-250
,
EC-588

Throttle position sensor circuit
22EC-210
,
EC-318
,
EC-477
,
EC-479
,
EC-574
Accelerator pedal position sensor circuit 3 2 1EC-440
,
EC-561
,
EC-567
,
EC-581
Knock sensor circuit 2 3EC-332
Crankshaft position sensor (POS) circuit 2 2EC-336