2011 INFINITI QX56 ECU

DLN-202
< UNIT REMOVAL AND INSTALLATION >[REAR FINAL DRIVE: R230]
REAR FINAL DRIVE
5. Set a suitable jack to rear final drive assembly.
CAUTION:
Never place a jack under the rear cover (aluminum case).
6. Remove the mounting bolts and nuts connecting to the suspen- sion member with power tool. And then, remove rear final drive
assembly.
CAUTION:
Secure rear final drive assembly to a suitable jack while
removing it.
INSTALLATION
Note the following, and installation is in the reverse order of removal.
CAUTION:
Check that there are no pinched or restricted areas on the breather hose caused by bending or wind-
ing when installing it.
 In (A) position, install the breather hose (1) until dimension (D) shown as follows.
CAUTION:
 Never reuse hose clamp.
 Install the hose clamp, wit h the tab facing downward.
 In (B) position, install the breather hose (2) until hose reaches the
plane tube surface connector.
CAUTION:
 Never reuse hose clamp.
 Install the hose clamp, with the tab facing righ tward and upward direction of the vehicle at 45°.
 In (C) position, install the breather hose (2) until dimension (E) shown as follows.
 Install breather hose (1) and (2), breather tube (3) and metal con- nector (4) as shown in the figure.
- Fix breather hose (2) with clip in (A) position CAUTION:
Never reuse clip.
- Install metal connector (4) to rear cover with a part to insert breather hose with facing vehicle left.
CAUTION:
Never reuse metal connector.
- Fix a point with paint mark (B) of breather tube (3) in (C) position.
- Fix breather tube (3) in (D) position.
 When oil leaks while removing final drive assembly, check oil level after the installation. Refer to DLN-193, "
Inspection".
JSDIA0132ZZ
: Vehicle front
D : 20 mm (0.79 in)
E : 20 mm (0.79 in)
: Vehicle front
JPDID0395ZZ
JPDID0396ZZ
Revision: 2010 May2011 QX56

DLN-210
< UNIT DISASSEMBLY AND ASSEMBLY >[REAR FINAL DRIVE: R230]
DIFFERENTIAL ASSEMBLY
16. Using the drift [SST: ST35271000 (J-26091)], drive side oil seals
until it becomes flush with the case end.
CAUTION:
 Never reuse oil seal.
 When installing, n ever incline oil seal.
 Apply multi-purpose grease onto oil seal lips, and gear oil
onto the circumference of oil seal.
17. Check and adjust drive gear runout, tooth contact, drive gear to drive pinion backlash, and total preload torque. Refer to DLN-
210, "Adjustment".
Recheck above items. Readjust the above description, if neces-
sary.
18. Apply sealant to mating surface of rear cover.  Use Genuine Silicone RTV or equivalent. Refer to GI-22,
"Recommended Chemical Products and Sealants".
CAUTION:
Remove old sealant adhering to mounting surfaces. Also
remove any moisture, oil, or foreign material adhering to
application and mounting surfaces.
19. Install rear cover on gear carrier and tighten mounting bolts.
20. Install side flange with the following procedure.
a. Attach the protector [SST: KV38108000 ( — )] to side oil seal.
b. After the side flange is inserted and the serrated part of side gear has engaged the serrated part of flange, remove the pro-
tector.
c. Insert the side flange until the se rrated part of the side flange
has engaged the serrated part of the side gear and remove the
protector.
NOTE:
When installation is completed, driving sound of the side flange
turns into a sound that seems to affect the whole final drive.
d. Confirm that the dimension of the side flanges (1) installation measurement (A) in the figure comes into the following.
AdjustmentINFOID:0000000006222423
TOTAL PRELOAD TORQUE
Before inspection and adjustment, drain gear oil.
1. Secure final drive assembly onto an attachment [SST: KV38100800 ( — )].
2. Remove side flanges.
3. Rotate drive pinion back and forth 2 to 3 times to check for unusual noise and rotation malfunction.
SPD560
PDIA0961E
SDIA0822E
A : 342.2 mm (13.47 in)
JSDIA0185ZZ
Revision: 2010 May2011 QX56

EC-2
DIRECT INJECTION GASOLINE SYSTEM : Sys-
tem Description .......................................................
36
FUEL PRESSURE CONTROL ..................................39
FUEL PRESSURE CONTROL : System Diagram
...
39
FUEL PRESSURE CONTROL : System Descrip-
tion ..........................................................................
39
COOLING FAN CONTROL .................................... ...40
COOLING FAN CONTROL : System Diagram .......41
COOLING FAN CONTROL : System Description ...41
ELECTRIC IGNITION SYST EM ................................41
ELECTRIC IGNITION SYSTEM :
System Diagram ................................................. ...
42
ELECTRIC IGNITION SYSTEM : System De-
scription ..................................................................
42
INTAKE VALVE TIMING CONTROL ..................... ...43
INTAKE VALVE TIMING CONTROL : System Di-
agram .....................................................................
43
INTAKE VALVE TIMING CONTROL : System De-
scription ..................................................................
43
VVEL SYSTEM ....................................... ...................43
VVEL SYSTEM : System Dia gram ........................44
VVEL SYSTEM : System De scription .....................44
EVAPORATIVE EMISSION SYSTEM .................... ...45
EVAPORATIVE EMISSION SYSTEM : System
Diagram ..................................................................
45
EVAPORATIVE EMISSION SYSTEM : System
Description ..............................................................
45
AIR CONDITIONING CUT CONTROL ................... ...46
AIR CONDITIONING CUT CONTROL : System
Diagram ..................................................................
47
AIR CONDITIONING CUT CONTROL : System
Description ..............................................................
47
AUTOMATIC SPEED CONTROL DEVICE (ASCD) ...47
AUTOMATIC SPEED CONTROL DEVICE (AS-
CD) : System Diagram ............................................
48
AUTOMATIC SPEED CONTROL DEVICE (AS-
CD) : System Description .......................................
48
CAN COMMUNICATION ........................................ ...48
CAN COMMUNICATION : System Description ......48
OPERATION ................................................... ...49
AUTMATIC SPEED CONTROL DEVICE (ASCD) . ...49
AUTMATIC SPEED CONTROL DEVICE (ASCD)
: Switch Name and Function ...................................
49
ON BOARD DIAGNOSTIC (OBD) SYSTEM .....51
Diagnosis Description .......................................... ...51
GST (Generic Scan Tool) .......................................51
DIAGNOSIS SYSTEM (ECM) ............................52
DIAGNOSIS DESCRIPTION .................................. ...52
DIAGNOSIS DESCRIPTION : 1st Trip Detection
Logic and Two Trip Detection Logic ........................
52
DIAGNOSIS DESCRIPTION : DTC and Freeze
Frame Data .............................................................
52
DIAGNOSIS DESCRIPTION : Counter System ......53
DIAGNOSIS DESCRIPTION : Driving Pattern ........58
DIAGNOSIS DESCRIPTION : System Readiness
Test (SRT) Code .................................................. ...
58
DIAGNOSIS DESCRIPTION : Malfunction Indica-
tor Lamp (MIL) ..................................................... ...
60
On Board Diagnosis Function .................................60
CONSULT-III Function ............................................63
ECU DIAGNOSIS INFORMATION .............72
ECM ................................................................ ...72
Reference Value .................................................. ...72
Fail-safe ..................................................................93
DTC Inspection Priority Chart .................................96
DTC Index ...............................................................98
Test Value and Test Limit ..................................104
VVEL CONTROL MODULE .............................110
Reference Value .................................................. .110
WIRING DIAGRAM ...................................114
ENGINE CONTROL SYSTEM ........................ ..114
Wiring Diagram .................................................... .114
BASIC INSPECTION .................................135
DIAGNOSIS AND REPAIR WORKFLOW ...... ..135
Work Flow ............................................................ .135
Diagnostic Work Sheet .........................................138
BASIC INSPECTION ...................................... ..139
Work Procedure ................................................... .139
ADDITIONAL SERVICE WHEN REPLACING
ECM ..................................................................
143
Description ........................................................... .143
Work Procedure ....................................................143
ADDITIONAL SERVICE WHEN REPLACING
VVEL CONTROL MODULE .............................
144
Description ........................................................... .144
Work Procedure ....................................................144
VIN REGISTRATION ........................................145
Description ........................................................... .145
Work Procedure ....................................................145
ACCELERATOR PEDAL RELEASED POSI-
TION LEARNING ............................................ ..
146
Description ........................................................... .146
Work Procedure ....................................................146
THROTTLE VALVE CLOSED POSITION
LEARNING .......................................................
147
Description ........................................................... .147
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

PRECAUTIONSEC-11
< PRECAUTION > [VK56VD]
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EC
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When connecting ECM harness connector (A), fasten (B) it
securely with a lever as far as it will go as shown in the figure.
-ECM (1)
- Loosen (C)
 When connecting or disconnect ing pin connectors into or
from ECM, never damage pin terminals (bends or break).
Check that there are not any bends or breaks on ECM pin ter-
minal, when connect ing pin connectors.
 Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge) volt-
age to develop in coil and cond enser, thus resulting in dam-
age to ICs.
 Keep engine control system harness at least 10 cm (4 in) away
from adjacent harness, to prevent engine control system mal-
functions due to receiving externa l noise, degraded operation
of ICs, etc.
 Keep engine control system parts and harness dry.
 Before replacing ECM, perform ECM Terminals and Reference
Value inspection and check that ECM functions properly.
Refer to EC-72, "
Reference Value".
 Handle mass air flow sensor carefully to avoid damage.
 Never clean mass air flow sensor with any type of detergent.
 Never disassemble electric th rottle control actuator.
 Even a slight leakage in the air intake system can cause seri-
ous incidents.
 Never shock or jar the camshaf t position sensor, crankshaft
position sensor.
 After performing each TROUBL E DIAGNOSIS, perform DTC
Confirmation Procedure or Component Function Check.
The DTC should not be displ ayed in the DTC Confirmation
Procedure if the repair is completed. The Component Func-
tion Check should be a good resu lt if the repair is completed.
JMBIA0029ZZ
PBIB0090E
MEF040D
SEF217U
Revision: 2010 May2011 QX56

EC-34
< SYSTEM DESCRIPTION >[VK56VD]
STRUCTURE AND OPERATION
On Board Refueling V apor Recovery (ORVR)
INFOID:0000000006217696
From the beginning of refueling, the air and vapor insi de the fuel tank go through refueling EVAP vapor cut
valve and EVAP/ORVR line to the EVAP canister. The vapor is absorbed by the EVAP canister and the air is
released to the atmosphere.
When the refueling has reached the full level of the fuel tank, the refueling EVAP vapor cut valve is closed and
refueling is stopped because of auto shut-off. The vapor which was absorbed by the EVAP canister is purged
during driving.
WARNING:
When conducting inspections below, be sure to observe the following:
 Put a “CAUTION: FLAMMABLE” sign in workshop.
 Never smoke while servicing fuel system. Keep open flames and sparks away from work area.
 Always furnish the workshop with a CO
2 fire extinguisher.
CAUTION:
 Before removing fuel line parts, carry out the following procedures:
- Put drained fuel in an explosion-pr oof container and put lid on securely.
- Release fuel pressure from fuel line. Refer to EC-153, "
Work Procedure".
- Disconnect battery ground cable.
 Always replace O-ring when the fuel gauge retainer is removed.
 Never kink or twist hose and tube when they are installed.
 Never tighten hose and clamps excessively to avoid damaging hoses.
 After installation, run engine an d check for fuel leaks at connections.
 Never attempt to top off the fuel tank after the fuel pump nozzle shuts off automatically.
Continued refueling may cause fu el overflow, resulting in fuel spray and possibly a fire.
PBIB1068E
Revision: 2010 May2011 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-51
< SYSTEM DESCRIPTION > [VK56VD]
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
Diagnosis DescriptionINFOID:0000000006217720
This system is an on board diagnostic system that re
cords exhaust emission-related diagnostic information
and detects a sensors/actuator-related malfunction. A ma lfunction is indicated by the malfunction indicator
lamp (MIL) and stored in ECU memory as a DTC. The diagnostic information can be obtained with the diag-
nostic tool (GST: Generic Scan Tool).
GST (Generic Scan Tool)INFOID:0000000006217721
When GST is connected with a data link connector equipped on the vehicle side, it will communicate with the
control unit equipped in the vehicle and then enable va rious kinds of diagnostic tests. Refer to GI-48, "
Descrip-
tion".
NOTE:
Service $0A is not applied for r egions where it is not mandated.
Revision: 2010 May2011 QX56

EC-52
< SYSTEM DESCRIPTION >[VK56VD]
DIAGNOSIS SYSTEM (ECM)
DIAGNOSIS SYSTEM (ECM)
DIAGNOSIS DESCRIPTION
DIAGNOSIS DESCRIPTION : 1st Trip Detect
ion Logic and Two Trip Detection Logic
INFOID:0000000006217722
When a malfunction is detected for the first time, 1st tr ip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MIL will not illuminate at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MIL illuminates. The MIL illu minates at the same time when the DTC is stored.
<2nd trip> The “trip” in the “Two Trip Detection Logic” means a driving mode in which self-diagnosis is per-
formed during vehicle operation. Specific on board diagnos tic items will cause the ECM to illuminate or blink
the MIL, and store DTC and Freeze Frame data, even in the 1st trip, as shown below.
×: Applicable —: Not applicable
DIAGNOSIS DESCRIPTION : DT C and Freeze Frame DataINFOID:0000000006217723
DTC AND 1ST TRIP DTC
The 1st trip DTC (whose number is the same as the DT C number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously , and the 1st trip DTC did not recur, the 1st trip DTC
will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is saved in the ECM memory. The MIL will not
light up (two trip detection logic). If the same malfunc tion is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are saved in the ECM memory and the MIL lights up. In other words,
the DTC is stored in the ECM memory and the MIL light s up when the same malfunction occurs in two consec-
utive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd
trips, only the 1st trip DTC will continue to be stored. Fo r malfunctions that blink or light up the MIL during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
For malfunctions in which 1st trip DTCs are displayed, refer to EC-98, "
DTC Index". These items are required
by legal regulations to continuous ly monitor the system/component. In addi tion, the items monitored non-con-
tinuously are also displayed on CONSULT-III.
1st trip DTC is specified in Service $07 of SAE J1979/ ISO 15031-5. 1st trip DTC detection occurs without illu-
minating the MIL and therefore does not warn the driver of a malfunction.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step 2, refer to EC-135, "
Work Flow". Then perform DTC Confirma-
tion Procedure or Component Function Check to try to duplicate the malfunction. If the malfunction is dupli-
cated, the item requires repair.
FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATA
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short term fuel trim, long term fuel trim, engine speed, vehicle speed, absolute throttle position, base
fuel schedule and intake air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are ca lled freeze frame data and displayed on CONSULT-III or
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-III screen.
Items MIL DTC 1st trip DTC
1st trip 2nd trip 1st trip
displaying 2nd trip
displaying 1st trip
displaying 2nd trip
displaying
Blinking Illuminate Blinking Illuminate
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0308 is
being detected ×
——— — — ×—
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0308 is
being detected ——
×—— ×——
One trip detection diagnoses (Re-
fer to EC-98, "
DTC Index".) —
×—— ×———
Except above — — — ×— ×× —
Revision: 2010 May2011 QX56