2011 INFINITI QX56 gas type

REPAIRING HIGH STRENGTH STEELBRM-5
< PRECAUTION >
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 The repair of reinforcements (such as side members) by heat- ing is not recommended, because it may weaken the compo-
nent. When heating is unavoidable, never heat HSS parts
above 550 °C (1,022 °F).
Verify heating temperature with a thermometer.
(Crayon-type and other similar type thermometer are appropri-
ate.)
 When straightening body panels, use caution in pul ling any HSS panel. Because HSS is very strong,
pulling may cause deformation in adjacent sections of the body. In this case, increase the number of
measuring points, and carefully pull the HSS panel.
 When cutting HSS panels, avoid gas (torch) cutting if possible.
Instead, use a saw to avoid weakening surrounding areas due
to heat. If gas (torch) cutting is unavoidable, allow a minimum
margin of 50 mm (1.97 in).
 When welding HSS panels, use spot welding whenever possi- ble in order to minimize weakening surrounding areas due to
heat.
If spot welding is impossible, use MIG. welding. Do not use
gas (torch) for welding because it is inferior in welding
strength.
 Spot welding on HSS panels is harder than that of an ordinary steel panel.
Therefore, when cutting spot welds on a HSS panel, use a low
speed high torque drill (1,000 to 1,200 rpm) to increase drill bit
durability and facilitate the operation.
PIIA0115E
PIIA0117E
PIIA0144E
PIIA0145E
Revision: 2010 May2011 QX56

EC-10
< PRECAUTION >[VK56VD]
PRECAUTIONS
CAUTION:
Comply with the following cautions to
prevent any error and malfunction.
 Install the xenon bulb securely. (Ins ufficient bulb socket installation may melt the bulb, the connec-
tor, the housing, etc. by high-v oltage leakage or corona discharge.)
 Never perform HID circuit in spection with a tester.
 Never touch the xenon bulb glass with ha nds. Never put oil and grease on it.
 Dispose of the used xenon bulb after packing it in thick vinyl without breaking it.
 Never wipe out dirt and cont amination with organic solven t (thinner, gasoline, etc.).
On Board Diagnostic (OBD) System of Engine and A/TINFOID:0000000006217652
The ECM has an on board diagnostic system. It will illuminate the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
 Always turn the ignition switch OFF and disconnect the negative battery cable before any repair or
inspection work. The open/short circuit of related sw itches, sensors, solenoid valves, etc. will cause
the MIL to illuminate.
 Always connect and lock the conn ectors securely after work. A loose (unlocked) connector will
cause the MIL to illuminate due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
 Certain systems and components, especially those related to OBD, may use a new style slide-lock-
ing type harness connector. For descripti on and how to disconnect, refer to EC-51, "
Diagnosis
Description".
 Always route and secure the harnesses properly afte r work. The interference of the harness with a
bracket, etc. may cause the MIL to illu minate due to the short circuit.
 Always connect rubber tubes properly after work. A misconnected or disconnected rubber tube may
cause the MIL to illuminate due to the malfunction of the EVAP system or fuel injection system, etc.
 Always erase the unnecessary malfunction information (repairs completed) from the ECM and TCM
(Transmission control module) before re turning the vehicle to the customer.
General PrecautionsINFOID:0000000006217653
Always use a 12 volt battery as power source.
 Never attempt to disconnect battery cables while engine is
running.
 Before connecting or disconnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative bat-
tery cable. Failure to do so may damage the ECM because
battery voltage is applied to ECM even if ignition switch is
turned OFF.
 Before removing parts, turn ig nition switch OFF and then dis-
connect battery ground cable.
 Never disassemble ECM.
 If a battery cable is disconnected, the memory will return to
the ECM value.
The ECM will now start to self-control at its initial value. Thus,
engine operation can vary slight ly in this case. However, this
is not an indication of a ma lfunction. Never replace parts
because of a slight variation.
 If the battery is disconnected, the following emission-related
diagnostic information will be lost within 24 hours.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
SEF289H
JMBIA0057ZZ
Revision: 2010 May2011 QX56

COMPONENT PARTSEC-21
< SYSTEM DESCRIPTION > [VK56VD]
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Accelerator Pedal
Position SensorINFOID:0000000006217658
The accelerator pedal position (APP) sensor is installed on the
accelerator pedal assembly. The sensor detects the accelerator
position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometer which transform the accelerator pedal
position into output voltage, and emit the voltage signals to the ECM.
The ECM judges the current opening angle of the accelerator pedal
from these signals and controls the throttle control motor based on
these signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The
ECM uses this signal for engine operations such as fuel cut.
Air Fuel Ratio (A/F) Sensor 1INFOID:0000000006217659
DESCRIPTION
The sensor element of the A/F sensor 1 is composed an electrode layer, which transports ions. It has a heater
in the element.
The sensor is capable of precise measurement = 1, but also in the lean and rich range. Together with its
control electronics, the sens or outputs a clear, continuous signal throughout a wide range.
The exhaust gas components diffuse through the diffusion layer at the sensor cell. An electrode layer is
applied voltage, and this current relative oxygen density in lean. Also this current relative hydrocarbon density
in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of approxi-
mately 760 °C (1,400 °F).
A/F SENSOR 1 HEATER
A/F sensor 1 heater is integrated in the sensor.
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F s ensor 1 element within the specified range.
ASCD Brake Switch & Stop Lamp Switch INFOID:0000000006217660
Stop lamp switch and ASCD brake switch are installed to brake pedal bracket.
When the brake pedal is depressed, ASCD brake switch is turned OFF and stop lamp switch is turned ON.
ECM detects the state of the brake pedal by those two types of input (ON/OFF signal).
ASCD Steering SwitchINFOID:0000000006217661
ASCD steering switch has variant values of electrical resistance for each button. ECM reads voltage variation
of switch, and determines which button is operated.
ASCD IndicatorsINFOID:0000000006217662
ASCD operation status is indicated by CRUISE indicator in combination meter.
ECM transmits the ASCD status signal to the combi nation meter via CAN communication according to ASCD
operation.
PBIB1741E
JSBIA0527GB
Revision: 2010 May2011 QX56

ECM
EC-95
< ECU DIAGNOSIS INFORMATION > [VK56VD]
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P062B ECM Type1
 Engine torque is limited.
 Idle engine speed is increased.
 Fuel injector power supply shut-off.
 High fuel pressure limitation.
Typ e2
 Engine torque is limited.
 Fuel injection shut-off of malfunction cylinder.
 Mixture ratio feedback control does not function.
 Idle engine speed is increased.
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.
P1087
P1088 VVEL control function VVEL of no
rmal bank is controlled at VVEL angle of abnormal bank.
Engine speed will not rise more than 3,500 rpm due to the fuel cut.
P1089
P1092 VVEL control shaft position
sensor VVEL value is maintained at a fixed angle.
Engine speed will not rise more than 3,500 rpm due to the fuel cut
P1197 Out of gas  Engine torque is limited.
 VVEL value is maintained at a fixed angle.
P1608 VVEL control shaft position
sensor VVEL actuator motor relay is turned off, an
d VVEL value is become at a minimum angle.
Engine speed will not rise more than 3,500 rpm due to the fuel cut.
P1090
P1093 VVEL actuator motor VVEL of no
rmal bank is controlled at VVEL angle of abnormal bank.
Engine speed will not rise more than 3,500 rpm due to the fuel cut.
VVEL actuator motor relay is turned off, an d VVEL value is become at a minimum angle.
Engine speed will not rise more than 3,500 rpm due to the fuel cut.
P1091 VVEL actuator motor rela
y VVEL actuator motor relay is turned off, an d VVEL value is become at a minimum angle.
Engine speed will not rise more than 3,500 rpm due to the fuel cut.
P1197 Out of gas  Engine torque is limited.
 VVEL value is maintained at a fixed angle.
P2101 Electric throttle control
function ECM 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 because of regulating the throttle open-
ing to 20 degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is being driven, it slows down gradually by fuel cut. After the vehicle
stops, the engine stalls.
The engine can restart in the N or P position, and engine speed will not exceed 1,000 rpm
or more.
P1290
P2100
P2103 Throttle 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.
P1606 VVEL control module VVEL
actuator motor relay is turned off, and VVEL value is become at a minimum angle.
Engine speed will not rise more than 3,500 rpm due to the fuel cut.
P1805 Brake switch ECM controls the electric throttle control
actuator by regulating the throttle opening to a
small range.
Therefore, acceleration will be poor.
Vehicle condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration
DTC No. Detected items Engine operating condition in fail-safe mode
Revision: 2010 May2011 QX56

EC-294
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0300, P0301, P0302, P
0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
When the gap is less than 13 mm (0.52 in), a spark might be generated even if the coil is malfunc-
tioning.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 6.
6.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a non-malfunctioning spark plug.
3. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded metal portion.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Check ignition coil, power transistor and their circuits. Refer to EC-506, "
Diagnosis Procedure".
7.CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
Is the inspection result normal?
YES >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-132, "
Spark Plug".
NO >> Repair or clean spark plug. Then GO TO 8.
8.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded portion.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-132, "
Spark
Plug".
9.CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-16, "
Inspection".
Is the inspection result normal?
YES >> GO TO 10.
NO >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
10.CHECK FUEL PRESSURE
1. Install all removed parts.
2. Check fuel pressure. Refer to EC-153, "
Work Procedure".
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check fuel hoses and fuel tubes for clogging.
Is the inspection result normal?
Spark should be generated.
SEF156I
Spark should be generated.
Revision: 2010 May2011 QX56

EC-310
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0420, P0430 THREE
WAY CATALYST FUNCTION
6. Remove all ignition coil harness connectors to avoi d the electrical discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 - 0.66 in) between the edge of the spark plug and grounded metal
portion as shown in the figure.
11. Crank engine for approximately 3 seconds, and check whether spark is generated between the spark plug and the grounded
metal portion.
CAUTION:
 Never place the spark plug and the ignition coil within 50
cm (19.7 in) each other. Be careful not to get an electrical
shock while checking, becau se the electrical discharge
voltage becomes 20 kV or more.
 It might damage the ignition coil if the gap of more than 17 mm (0.66 in) is made.
NOTE:
When the gap is less than 13 mm (0.52 in), a spark might be generated even if the coil is malfunc-
tioning.
Is the inspection result normal?
YES >> GO TO 10.
NO >> GO TO 7.
7.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a non-malfunctioning spark plug.
3. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded metal portion.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Check ignition coil, power transistor and their circuits. Refer to EC-506, "
Diagnosis Procedure".
8.CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
Is the inspection result normal?
YES >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-132, "
Spark Plug".
NO >> Repair or clean spark plug. Then GO TO 9.
9.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded portion.
Is the inspection result normal?
YES >> INSPECTION END Spark should be generated.
JMBIA0066GB
Spark should be generated.
SEF156I
Spark should be generated.
Revision: 2010 May2011 QX56

EM-16
< BASIC INSPECTION >
COMPRESSION PRESSURE
COMPRESSION PRESSURE
InspectionINFOID:0000000006289521
1. Warm up engine thoroughly. Then, stop it.
2. Release fuel pressure. Refer to EC-153, "
Work Procedure".
CAUTION:
If CONSULT-III is not used to release fuel pr essure leave the fuel pump fuse disconnected until
step 7.
3. Remove fuel pump fuse in IPDM E/R. NOTE:
 For the fuse number, refer to EC-114, "
Wiring Diagram".
 For the fuse arrangement, refer to PG-143, "
Fuse, Connector and Terminal Arrangement".
4. Remove engine cover. Refer to EM-25, "
Exploded View".
5. Remove ignition coil and spark plug from each cylinder. Refer to EM-29, "
Exploded View".
6. Connect engine tachometer (not required in use of CONSULT-III).
7. Install the compression tester with Tool [SST: EG15050500 (J- 45402)] into the spark plug hole.
8. Measure compression pressure using compressi on gauge connected with flexible type adapter (commer-
cial service tool).
9. With accelerator pedal fully depressed, turn ignition switch to “START” for cranking. When the gauge pointer stabilizes, read the compression pressure and the engine rpm. Perform these steps to check each
cylinder.
CAUTION:
 Measure a six-cylinder under the same conditio ns since a measurement depends on measure-
ment conditions (engine water temperature, etc.).
 Always use a fully changed battery to obtain the specified engine speed.
 If the engine speed is out of the specified range, c heck battery liquid for proper gravity. Check the
engine speed again with normal battery gravity. Refer to PG-159, "
How to Handle Battery".
 If compression pressure is below the minimum value, check valve clearances and parts associated with combustion chamber (valve, valve seat, piston, pi ston ring, cylinder bore, cylinder head, cylinder head
gasket). After checking, measure compression pressure again.
 If a cylinder has low compression pressure, pour a small amount of engine oil into the spark plug hole of the cylinder to re-check it for compression.
- If the added engine oil improves the compression, pi ston rings may be worn out or damaged. Check pis-
ton rings and replace if necessary. Refer to EM-107, "
Disassembly and Assembly".
- If the compression pressure remains at low level despite the addition of engine oil, valves may be mal- functioning. Check valves for damage. Replace valve or valve seat accordingly. Refer to EM-107, "
Dis-
assembly and Assembly".
 If two adjacent cylinders have respectively low co mpression pressure and their compression remains
low even after the addition of engine oil, cylinder head gaskets are leaking. In such a case, replace cyl-
inder head gaskets. Refer to EM-87, "
Removal and Installation".
10. After inspection is completed, install removed parts.
11. Start the engine, and check that the engine runs smoothly.
WBIA0605E
Compression pressure : Refer to EM-132, "GeneralSpecification".
Revision: 2010 May2011 QX56

OIL PAN (UPPER)EM-59
< REMOVAL AND INSTALLATION >
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a. Use a scraper (A) to remove old liquid gasket from mating sur-
faces.
 Also remove the old liquid gasket from mating surface of cylin-der block.
 Remove old liquid gasket from the bolt holes and threads.
CAUTION:
Never scratch or damage th e mating surfaces when clean-
ing off old liquid gasket.
b. Install new O-rings on the bottom of cylinder block and oil pump.
c. Apply a continuous bead of liquid gasket with tube pre sser (commercial service tool) to the cylinder block
mating surfaces of oil pan (upper) to a limited portion as shown in the figure.
Use Genuine RTV silicone sealant or equivalent. Refer to GI-22, "
Recommended Chemical Prod-
ucts and Sealants".
CAUTION:
Attaching must be done with in 5 minutes after coating.
d. Tighten mounting bolts in numerical order as shown in the fig- ure.
CAUTION:
Install avoiding misal ignment of O-rings.
NOTE:
Tighten mounting bolts No. 1 and 2 in two steps. The numerical
order No. 9 and 16 shown second steps.
 There are four types of mounting bolts. Refer to the following for locating bolts.
e. Tighten transmission joint bolts.
f. Install rear plate cover.
2. Install oil strainer.
JPBIA3503ZZ
a. : 5.5 - 7.5 mm (0.217 - 0.295 in) b. : φ4.0 - 5.0 mm (0.157 - 0.197 in)
: Engine front
JPBIA3504ZZ
: Engine front
JPBIA3502ZZ
Order number for tightening 17, 18 2 (16), 3, 5, 6, 7, 8, 10,
11, 14, 15 1(9), 4 12, 13
Bolt size M6 M8
Bolt length 45 mm (1.77 in) 25 mm (0.98 in) 30.0 mm (1.18 in) 120 mm (4.72 in)
Tightening torque 9.0 N· (0.92 kg-m, 80
in-lb) 22.0 N·m (2.2 kg-m, 16 ft-lb)
Revision: 2010 May2011 QX56