2011 INFINITI QX56 engine

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CONTENTS
ENGINE CONTROL SYSTEM
VK56VD
PRECAUTION ................ ...............................
9
PRECAUTIONS .............................................. .....9
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
9
Precaution for Procedure without Cowl Top Cover ......9
Precautions For Xenon Headlamp Service ...............9
On Board Diagnostic (OBD) System of Engine
and A/T ....................................................................
10
General Precautions ...............................................10
PREPARATION ...........................................14
PREPARATION .............................................. ....14
Special Service Tools .......................................... ....14
Commercial Service Tools ......................................14
SYSTEM DESCRIPTION .............................16
COMPONENT PARTS ................................... ....16
Component Parts Location .................................. ....16
Component Description ...........................................19
Accelerator Pedal Position Sensor ..........................21
Air Fuel Ratio (A/F) Sensor 1 ..................................21
ASCD Brake Switch & Stop Lamp Switch ...............21
ASCD Steering Switch ............................................21
ASCD Indicators ......................................................21
Battery Current Sensor (With Battery Tempera-
ture Sensor) ............................................................
22
Camshaft Position Sensor .......................................22
Crankshaft Position Sensor .....................................23
ECM ........................................................................23
Electric Throttle Control Actuator ............................23
Electrically-controlled cooling fan coupling .............24
Engine Coolant Temperature Sensor ......................25
Engine Oil Temperature Sensor ..............................25
EVAP Control System Pressure Sensor .................26
EVAP Canister Vent Control Valve .........................26
EVAP Canister Purge Volume Control Solenoid
Valve .................................................................... ....
26
Fuel Injector .............................................................26
Fuel Level Sensor ....................................................26
Fuel Pump Control Module ......................................27
Fuel Rail Pressure Sensor .......................................27
Fuel Tank Temperature Sensor ...............................27
Heated Oxygen Sensor 2 ........................................27
High Pressure Fuel Pump .......................................28
ICC Brake Switch & Stop Lamp Switch ...................29
ICC Steering Switch ................................................29
Ignition Coil With Power Transistor .........................29
Intake Valve Timing Control Solenoid Valve ...........29
Knock Sensor ...................................................... ....30
Low Fuel Pressure Sensor ......................................30
Low Pressure Fuel Pump ........................................30
Malfunction Indicator Lamp (MIL) ............................30
Manifold Absolute Pressure Sensor ........................31
Mass Air Flow Sensor (With Intake Air Tempera-
ture Sensor) .............................................................
31
Power Steering Pressure (PSP) Sensor ..................31
Refrigerant Pressure Sensor ............................... ....32
VVEL Actuator Motor ...............................................32
VVEL Actuator Motor Relay .....................................32
VVEL Control Module ..............................................32
VVEL Control Shaft Position Sensor .......................32
STRUCTURE AND OPERATION .....................33
Positive Crankcase Ventilation ................................33
On Board Refueling Vapor Recovery (ORVR) ........34
SYSTEM ............................................................35
ENGINE CONTROL SYSTEM ........................ ...........35
ENGINE CONTROL SYSTEM : System Diagram ....35
ENGINE CONTROL SYSTEM : System Descrip-
tion ...........................................................................
35
DIRECT INJECTION GASOLINE SYSTEM .......... ....36
DIRECT INJECTION GASOLINE SYSTEM :
System Diagram .....................................................
36
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-4
Component Inspection (Engine Coolant Tempera-
ture Sensor) ...........................................................
216
P0117, P0118 ECT SENSOR ..........................217
DTC Logic ............................................................ ..217
Diagnosis Procedure .............................................217
Component Inspection (Engine Coolant Tempera-
ture Sensor) ...........................................................
218
P0122, P0123 TP SENSOR .............................219
DTC Logic ............................................................ ..219
Diagnosis Procedure .............................................219
Component Inspection (Throttle Position Sensor) ..220
P0125 ECT SENSOR .......................................222
DTC Logic ............................................................ ..222
Diagnosis Procedure .............................................222
Component Inspection (Engine Coolant Tempera-
ture Sensor) ...........................................................
223
P0127 IAT SENSOR ........................................224
DTC Logic ............................................................ ..224
Diagnosis Procedure .............................................224
Component Inspection (Intake Air Temperature
Sensor) ..................................................................
225
P0128 THERMOSTAT FUNCTION .................226
DTC Logic ............................................................ ..226
Diagnosis Procedure .............................................227
Component Inspection (Engine Coolant Tempera-
ture Sensor) ...........................................................
227
P0130, P0150 A/F SENSOR 1 .........................228
DTC Logic ............................................................ ..228
Component Function Check ..................................229
Diagnosis Procedure .............................................230
P0131, P0151 A/F SENSOR 1 .........................232
DTC Logic ............................................................ ..232
Diagnosis Procedure .............................................233
P0132, P0152 A/F SENSOR 1 .........................235
DTC Logic ............................................................ ..235
Diagnosis Procedure .............................................236
P0133, P0153 A/F SENSOR 1 .........................238
DTC Logic ............................................................ ..238
Diagnosis Procedure .............................................239
P0137, P0157 HO2S2 ......................................243
DTC Logic ............................................................ ..243
Component Function Check ..................................244
Diagnosis Procedure .............................................245
Component Inspection (HO2 sensor 2) .................246
P0138, P0158 HO2S2 ......................................249
DTC Logic ............................................................ ..249
Component Function Check ..................................251
Diagnosis Procedure .............................................251
Component Inspection (HO2 sensor 2) .................254
P0139, P0159 HO2S2 .......................................257
DTC Logic ............................................................ .257
Component Function Check .................................258
Diagnosis Procedure .............................................259
Component Inspection (HO2 sensor 2) ................260
P0171, P0174 FUEL INJECTION SYSTEM
FUNCTION ........................................................
263
DTC Logic ............................................................ .263
Diagnosis Procedure .............................................264
P0172, P0175 FUEL INJECTION SYSTEM
FUNCTION ........................................................
267
DTC Logic ............................................................ .267
Diagnosis Procedure .............................................268
P0181 FTT SENSOR ........................................271
DTC Logic ............................................................ .271
Diagnosis Procedure .............................................271
Component Inspection (Fuel Tank Temperature
Sensor) .................................................................
273
P0182, P0183 FTT SENSOR ............................274
DTC Logic ............................................................ .274
Diagnosis Procedure .............................................274
Component Inspection (Fuel Tank Temperature
Sensor) .................................................................
275
P0190, P0192, P0193 FRP SENSOR ...............276
DTC Logic ............................................................ .276
Diagnosis Procedure .............................................276
Component Inspection (Fuel Rail Pressure Sen-
sor) ........................................................................
278
P0191 FRP SENSOR .......................................279
DTC Logic ............................................................ .279
Diagnosis Procedure .............................................279
Component Inspection (Fuel Rail Pressure Sen-
sor) ........................................................................
281
P0196 EOT SENSOR .......................................283
DTC Logic ............................................................ .283
Diagnosis Procedure .............................................284
Component Inspection (Engine Oil Temperature
Sensor) .................................................................
284
P0197, P0198 EOT SENSOR ...........................285
DTC Logic ............................................................ .285
Diagnosis Procedure .............................................285
Component Inspection (Engine Oil Temperature
Sensor) .................................................................
286
P0201, P0202, P0203, P0204, P0205, P0206,
P0207, P0208 INJECTOR ................................
287
DTC Logic ............................................................ .287
Diagnosis Procedure .............................................287
P0222, P0223 TP SENSOR ..............................288
DTC Logic ............................................................ .288
Diagnosis Procedure .............................................288
Component Inspection (Throttle Position Sensor) .289
Revision: 2010 May2011 QX56

EC-5
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P0300, P0301, P0302, P0303, P0304, P0305,
P0306, P0307, P0308 MISFIRE ..................... ..
291
DTC Logic ........................................................... ..291
Diagnosis Procedure .............................................292
P0327, P0328, P0332, P0333 KS ....................297
DTC Logic ........................................................... ..297
Diagnosis Procedure .............................................297
Component Inspection (Knock Sensor) ................298
P0335 CKP SENSOR .......................................299
DTC Logic ........................................................... ..299
Diagnosis Procedure .............................................299
Component Inspection (Crankshaft Position Sen-
sor) ........................................................................
301
P0340, P0345 CMP SENSOR ..........................303
DTC Logic ........................................................... ..303
Diagnosis Procedure .............................................304
Component Inspection (Camshaft Position Sen-
sor) ........................................................................
306
P0420, P0430 THREE WAY CATALYST
FUNCTION .......................................................
307
DTC Logic ........................................................... ..307
Component Function Check ..................................308
Diagnosis Procedure .............................................309
P0441 EVAP CONTROL SYSTEM ..................312
DTC Logic ........................................................... ..312
Component Function Check ..................................313
Diagnosis Procedure .............................................314
P0443 EVAP CANISTER PURGE VOLUME
CONTROL SOLENOID VALVE .......................
317
DTC Logic ........................................................... ..317
Diagnosis Procedure .............................................318
Component Inspection (EVAP Canister Purge
Volume Control Solenoid Valve) ...........................
320
P0444, P0445 EVAP CANISTER PURGE
VOLUME CONTROL SOLENOID VALVE .......
322
DTC Logic ........................................................... ..322
Diagnosis Procedure .............................................322
Component Inspection (EVAP Canister Purge
Volume Control Solenoid Valve) ...........................
323
P0447 EVAP CANISTER VENT CONTROL
VALVE ..............................................................
325
DTC Logic ........................................................... ..325
Diagnosis Procedure .............................................325
Component Inspection (EVAP Canister Vent Con-
trol Valve) ............................................................ ..
327
P0448 EVAP CANISTER VENT CONTROL
VALVE ..............................................................
329
DTC Logic ........................................................... ..329
Diagnosis Procedure .............................................329
Component Inspection (EVAP Canister Vent Con-
trol Valve) ............................................................ ..
331
P0451 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
333
DTC Logic ............................................................ ..333
Diagnosis Procedure .............................................333
Component Inspection (EVAP Control System
Pressure Sensor) ................................................. ..
335
P0452 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
336
DTC Logic ..............................................................336
Diagnosis Procedure .............................................337
Component Inspection (EVAP Control System
Pressure Sensor) ................................................. ..
339
P0453 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
341
DTC Logic ..............................................................341
Diagnosis Procedure .............................................342
Component Inspection (EVAP Control System
Pressure Sensor) ................................................. ..
345
P0456 EVAP CONTROL SYSTEM .................346
DTC Logic ..............................................................346
Diagnosis Procedure .............................................347
Component Inspection (Fuel Filler Cap) ................350
P0460 FUEL LEVEL SENSOR .......................352
DTC Logic ............................................................ ..352
Diagnosis Procedure .............................................352
P0461 FUEL LEVEL SENSOR .......................353
DTC Logic ..............................................................353
Component Function Check ..................................353
Diagnosis Procedure .............................................354
P0462, P0463 FUEL LEVEL SENSOR ...........355
DTC Logic ..............................................................355
Diagnosis Procedure .............................................355
P0500 VSS ......................................................356
Description ........................................................... ..356
DTC Logic ..............................................................356
Component Function Check ..................................357
Diagnosis Procedure .............................................357
P0506 ISC SYSTEM ........................................358
Description .............................................................358
DTC Logic ..............................................................358
Diagnosis Procedure .............................................358
P0507 ISC SYSTEM ........................................360
Description .............................................................360
DTC Logic ..............................................................360
Diagnosis Procedure .............................................360
P050E COLD START CONTROL ...................362
Description .............................................................362
DTC Logic ..............................................................362
Diagnosis Procedure .............................................362
P0524 ENGINE OIL PRESSURE ....................364
Revision: 2010 May2011 QX56

EC-6
DTC Logic ..............................................................364
Diagnosis Procedure .............................................365
P0527 COOLING FAN SPEED SENSOR .......367
DTC Logic ............................................................ ..367
Diagnosis Procedure .............................................367
Component Inspection (Cooling Fan Speed Sen-
sor) ........................................................................
369
P0550 PSP SENSOR .......................................371
DTC Logic ............................................................ ..371
Diagnosis Procedure .............................................371
Component Inspection (Power Steering Pressure
Sensor) ..................................................................
373
P0603 ECM POWER SUPPLY ........................374
DTC Logic ............................................................ ..374
Diagnosis Procedure .............................................374
P0605 ECM ......................................................376
DTC Logic ............................................................ ..376
Diagnosis Procedure .............................................376
P0607 ECM ......................................................378
DTC Logic ............................................................ ..378
Diagnosis Procedure .............................................378
P0611 ECM PROTECTION .............................379
Description ........................................................... ..379
DTC Logic ..............................................................379
Diagnosis Procedure .............................................379
P062B ECM .....................................................380
Description ........................................................... ..380
DTC Logic ..............................................................380
Diagnosis Procedure .............................................380
P0643 SENSOR POWER SUPPLY .................381
DTC Logic ............................................................ ..381
Diagnosis Procedure .............................................381
P0850 PNP SWITCH .......................................383
Description ........................................................... ..383
DTC Logic ..............................................................383
Component Function Check ..................................384
Diagnosis Procedure .............................................384
P1087, P1088 VVEL SYSTEM ........................386
DTC Logic ............................................................ ..386
Diagnosis Procedure .............................................386
P1089, P1092 VVEL CONTROL SHAFT PO-
SITION SENSOR .............................................
387
DTC Logic ............................................................ ..387
Diagnosis Procedure .............................................387
P1090, P1093 VVEL ACTUATOR MOTOR .....390
DTC Logic ............................................................ ..390
Diagnosis Procedure .............................................390
Component Inspection (VVEL ACTUATOR MO-
TOR ASSEMBLY) .................................................
392
Component Inspection (VVEL ACTUATOR
HOUSING ASSEMBLY) ......... ...............................
392
P1091 VVEL ACTUATOR MOTOR RELAY ... ..393
DTC Logic ............................................................ .393
Diagnosis Procedure .............................................393
Component Inspection (VVEL Actuator Motor Re-
lay) ....................................................................... .
395
P1148, P1168 CLOSED LOOP CONTROL .....396
DTC Logic ............................................................ .396
Diagnosis Procedure .............................................396
P1197 OUT OF GAS ........................................397
Description ........................................................... .397
DTC Logic .............................................................397
Diagnosis Procedure .............................................398
P1212 TCS COMMUNICATION LINE ..............399
Description ........................................................... .399
DTC Logic .............................................................399
Diagnosis Procedure .............................................399
P1217 ENGINE OVER TEMPERATURE .........400
DTC Logic ............................................................ .400
Component Function Check .................................400
Diagnosis Procedure .............................................401
P1220 FUEL PUMP CONTROL MODULE
(FPCM) ..............................................................
403
DTC Logic ............................................................ .403
Diagnosis Procedure .............................................403
Component Inspection (FPCM) ............................405
P1225 TP SENSOR ..........................................406
DTC Logic ............................................................ .406
Diagnosis Procedure .............................................406
P1226 TP SENSOR ..........................................407
DTC Logic ............................................................ .407
Diagnosis Procedure .............................................407
P1421 COLD START CONTROL .....................408
Description ........................................................... .408
DTC Logic .............................................................408
Diagnosis Procedure .............................................408
P1423, P1424 COLD START CONTROL ........410
Description ........................................................... .410
DTC Logic .............................................................410
Diagnosis Procedure .............................................410
P1550 BATTERY CURRENT SENSOR ...........412
DTC Logic ............................................................ .412
Diagnosis Procedure .............................................412
Component Inspection (Battery Current Sensor) ..414
P1551, P1552 BATTERY CURRENT SEN-
SOR ..................................................................
416
DTC Logic ............................................................ .416
Diagnosis Procedure .............................................416
Component Inspection (Battery Current Sensor) ..419
Revision: 2010 May2011 QX56

EC-8
P2A00, P2A03 A/F SENSOR 1 .......................487
DTC Logic ............................................................ ..487
Diagnosis Procedure .............................................487
ASCD BRAKE SWITCH ................................. .490
Component Function Check ................................ ..490
Diagnosis Procedure .............................................490
Component Inspection (ASCD Brake Switch) .......491
ASCD INDICATOR ..........................................492
Component Function Check ................................ ..492
Diagnosis Procedure .............................................492
ELECTRICAL LOAD SIGNAL .........................493
Description ........................................................... ..493
Component Function Check ..................................493
Diagnosis Procedure .............................................493
ELECTRICALLY-CONTROLLED COOLING
FAN COUPLING ..............................................
495
Component Function Check ................................ ..495
Diagnosis Procedure .............................................495
FUEL INJECTOR .............................................498
Component Function Check ................................ ..498
Diagnosis Procedure .............................................498
Component Inspection ...........................................499
HIGH PRESSURE FUEL PUMP ......................501
Component Function Check ................................ ..501
Diagnosis Procedure .............................................501
Component Inspection ...........................................502
ICC BRAKE SWITCH ......................................503
Component Function Check ................................ ..503
Diagnosis Procedure .............................................503
Component Inspection (ICC Brake Switch) ...........505
IGNITION SIGNAL ...........................................506
Component Function Check ................................ ..506
Diagnosis Procedure .............................................506
Component Inspection (Ignition Coil with Power
Transistor) .............................................................
509
Component Inspection (Condenser) ......................510
INFORMATION DISPLAY (ASCD) ..................511
Component Function Check ................................ ..511
Diagnosis Procedure .............................................511
LOW PRESSURE FUEL PUMP ......................512
Component Function Check ................................ ..512
Diagnosis Procedure .............................................512
Component Inspection (Low Pressure Fuel Pump)
..
513
Component Inspection (FPCM) .............................514
MALFUNCTION INDICATOR LAMP ...............515
Component Function Check ................................ ..515
Diagnosis Procedure .............................................515
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) .....................................................
516
Component Function Check ................................ .516
Diagnosis Procedure .............................................516
Component Inspection (EVAP Vapor Cut Valve) . .518
REFRIGERANT PRESSURE SENSOR ......... ..520
Component Function Check ................................ .520
Diagnosis Procedure .............................................520
SNOW MODE SWITCH ....................................522
Description ........................................................... .522
Component Function Check .................................522
Diagnosis Procedure .............................................522
Component Inspection ..........................................523
SYMPTOM DIAGNOSIS ...........................524
ENGINE CONTROL SYSTEM SYMPTOMS .. ..524
Symptom Table .................................................... .524
NORMAL OPERATING CONDITION ...............529
Description ........................................................... .529
PERIODIC MAINTENANCE ......................530
IDLE SPEED .......................... ...........................530
Inspection ............................................................. .530
IGNITION TIMING .............................................531
Inspection ............................................................. .531
EVAP LEAK CHECK ........................................532
Inspection ............................................................. .532
POSITIVE CRANKCASE VENTILATION .........534
Inspection ............................................................. .534
REMOVAL AND INSTALLATION .............535
ECM ................................................................ ..535
Removal and Installation ...................................... .535
VVEL CONTROL MODULE .............................536
Removal and Installation ...................................... .536
FUEL PUMP CONTROL MODULE (FPCM) ....537
Removal and Installation ...................................... .537
SERVICE DATA AND SPECIFICATIONS
(SDS) ........ .................................................
538
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ..
538
Idle Speed ............................................................ .538
Ignition Timing .......................................................538
Calculated Load Value ..........................................538
Mass Air Flow Sensor ...........................................538
Revision: 2010 May2011 QX56

PRECAUTIONSEC-9
< PRECAUTION > [VK56VD]
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental
Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006219727
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minutes before performing any service.
Precaution for Procedur e without Cowl Top CoverINFOID:0000000006217650
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precautions For Xenon Headlamp ServiceINFOID:0000000006217651
WARNING:
Comply with the follow ing warnings to prevent any serious accident.
 Disconnect the battery cable (neg ative terminal) or the power supply fuse before installing, remov-
ing, or touching the xenon headlamp (bulb included). The xenon headlamp contains high-voltage
generated parts.
 Never work with wet hands.
 Check the xenon headlamp ON-OFF status after assem bling it to the vehicle. Never turn the xenon
headlamp ON in other conditions. Connect th e power supply to the vehicle-side connector.
(Turning it ON outside the lamp case m ay cause fire or visual impairments.)
 Never touch the bulb glass immediately afte r turning it OFF. It is extremely hot.
PIIB3706J
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