2009 INFINITI QX56 fuel

CHG
POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM
CHG-7
< FUNCTION DIAGNOSIS >
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POWER GENERATION VOLTAG
E VARIABLE CONTROL SYSTEM
System DiagramINFOID:0000000003776545
System DescriptionINFOID:0000000003776546
Power generation variable voltage control system has been adopted. By varying the voltage to the generator,
engine load due to power generation of the generator is reduced and fuel consumption is decreased.
NOTE:
When any malfunction is detected in the power generat ion variable voltage control system, power generation
is performed according to the characterist ic of the IC regulator in the generator.
Component DescriptionINFOID:0000000003776547
ALMIA0057GB
Component part Description
Battery current sensor The battery current sensor is installed on the battery cable at the
negative terminal. The battery current sensor detects the charg-
ing/discharging current of the battery and sends a voltage signal
to the ECM according to the current value detected.
ECM The battery current sensor detects the charging/discharging cur-
rent of the battery. The ECM judges the battery condition based on
this signal.
The ECM judges whether to request more output via the power
generation voltage variable control according to the battery condi-
tion.
When performing the power generation voltage variable control,
the ECM calculates the target power generation voltage according
to the battery condition and sends the calculated value as the pow-
er generation command value to the IPDM E/R.
IPDM E/R The IPDM E/R converts the received power generation command
value into a pulse width modulated (PWM) command signal and
sends it to the IC regulator.
Generator (IC regulator) The IC regulator controls the power generation voltage by the tar-
get power generation voltage based on the received PWM com-
mand signal.
When there is no PWM command signal, the generator performs
the normal power generation according to the characteristic of the
IC regulator.
Revision: December 20092009 QX56

EC-1
ENGINE
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SECTION EC
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CONTENTS
ENGINE CONTROL SYSTEM
VK56DE
BASIC INSPECTION ....... .............................
8
DIAGNOSIS AND REPAIR WORKFLOW ..... .....8
Trouble Diagnosis Introduction ........................... ......8
INSPECTION AND ADJUSTMENT ....................13
Basic Inspection .................................................. ....13
Idle Speed and Ignition Timing Check ....................17
Procedure After Replacing ECM .............................17
VIN Registration ......................................................17
Accelerator Pedal Released Position Learning .......18
Throttle Valve Closed Position Learning .................18
Idle Air Volume Learning .........................................18
FUNCTION DIAGNOSIS ..............................21
ENGINE CONTROL SYSTEM ........................ ....21
System Diagram .................................................. ....21
Engine Control Component Parts Location .............22
MULTIPORT FUEL INJECTION SYSTEM .........28
System Description ............................................. ....28
ELECTRIC IGNITION SYSTEM ..................... ....31
System Description ............................................. ....31
AIR CONDITIONING CUT CONTROL ...............32
Input/Output Signal Chart .................................... ....32
System Description .................................................32
AUTOMATIC SPEED CONTROL DEVICE
(ASCD) ...............................................................
33
System Description ............................................. ....33
Component Description ...........................................34
CAN COMMUNICATION ....................................35
System Description ............................................. ....35
COOLING FAN CONTROL ................................36
Description .......................................................... ....36
EVAPORATIVE EMISSION SYSTEM ...............37
Description ........................................................... ....37
INTAKE VALVE TIMING CONTROL ................40
Description ...............................................................40
ON BOARD DIAGNOSTIC (OBD) SYSTEM ....41
Introduction ..............................................................41
Two Trip Detection Logic .........................................41
Emission-related Diagnostic Information .................42
Malfunction Indicator Lamp (MIL) ............................55
OBD System Operation Chart .................................58
CONSULT-III Function (ENGINE) ...........................63
Generic Scan Tool (GST) Function .........................72
COMPONENT DIAGNOSIS .........................74
TROUBLE DIAGNOSIS - SPECIFICATION
VALUE ...............................................................
74
Description ........................................................... ....74
Testing Condition .....................................................74
Inspection Procedure ...............................................74
Diagnosis Procedure ...............................................75
POWER SUPPLY AND GROUND CIRCUIT ....82
Diagnosis Procedure ...............................................82
Ground Inspection ...................................................85
U1000, U1001 CAN COMM CIRCUIT ...............86
Description ...............................................................86
On Board Diagnosis Logic .......................................86
DTC Confirmation Procedure ..................................86
Diagnosis Procedure ...............................................86
P0011, P0021 IVT CONTROL ...........................87
On Board Diagnosis Logic .......................................87
DTC Confirmation Procedure ..................................87
Diagnosis Procedure ...............................................88
Component Inspection .............................................92
P0031, P0032, P0051, P0052 A/F SENSOR 1
HEATER ............................................................
94
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EC-3
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Overall Function Check .......................................
..
158
Diagnosis Procedure .............................................159
Component Inspection ..........................................162
P0139, P0159 HO2S2 ......................................164
Component Description ....................................... ..164
On Board Diagnosis Logic ....................................164
DTC Confirmation Procedure ................................164
Overall Function Check .........................................165
Diagnosis Procedure .............................................165
Component Inspection ..........................................167
P0171, P0174 FUEL INJECTION SYSTEM
FUNCTION .......................................................
169
On Board Diagnosis Logic .................................. ..169
DTC Confirmation Procedure ................................169
Diagnosis Procedure .............................................170
P0172, P0175 FUEL INJECTION SYSTEM
FUNCTION .......................................................
174
On Board Diagnosis Logic .................................. ..174
DTC Confirmation Procedure ................................174
Diagnosis Procedure .............................................175
P0181 FTT SENSOR ........................................179
Component Description ....................................... ..179
On Board Diagnosis Logic ....................................179
DTC Confirmation Procedure ................................179
Diagnosis Procedure .............................................180
Component Inspection ..........................................181
P0182, P0183 FTT SENSOR ...........................182
Component Description ....................................... ..182
On Board Diagnosis Logic ....................................182
DTC Confirmation Procedure ................................182
Diagnosis Procedure .............................................182
Component Inspection ..........................................184
P0222, P0223 APP SENSOR ...........................185
Component Description ....................................... ..185
On Board Diagnosis Logic ....................................185
DTC Confirmation Procedure ................................185
Diagnosis Procedure .............................................185
Component Inspection ..........................................188
P0300, P0301, P0302, P0303, P0304, P0305,
P0306, P0307, P0308 MISFIRE .......................
189
On Board Diagnosis Logic .................................. ..189
DTC Confirmation Procedure ................................189
Diagnosis Procedure .............................................190
P0327, P0328, P0332, P0333 KS ....................195
Component Description ....................................... ..195
On Board Diagnosis Logic ....................................195
DTC Confirmation Procedure ................................195
Diagnosis Procedure .............................................195
Component Inspection ..........................................197
P0335 CKP SENSOR (POS) ............................198
Component Description ....................................... ..198
On Board Diagnosis Logic ....................................198
DTC Confirmation Procedure .............................. ..198
Diagnosis Procedure .............................................199
Component Inspection ...........................................200
P0340 CMP SENSOR (PHASE) .....................202
Component Description .........................................202
On Board Diagnosis Logic .....................................202
DTC Confirmation Procedure ................................202
Diagnosis Procedure .............................................203
Component Inspection ...........................................204
P0420, P0430 THREE WAY CATALYST
FUNCTION ......................................................
206
On Board Diagnosis Logic ................................... ..206
DTC Confirmation Procedure ................................206
Overall Function Check .........................................207
Diagnosis Procedure .............................................207
P0441 EVAP CONTROL SYSTEM .................210
System Description ................................................210
On Board Diagnosis Logic .....................................210
DTC Confirmation Procedure ................................210
Overall Function Check .........................................211
Diagnosis Procedure .............................................211
P0442 EVAP CONTROL SYSTEM .................215
On Board Diagnosis Logic .....................................215
DTC Confirmation Procedure ................................215
Diagnosis Procedure .............................................216
Component Inspection ...........................................221
P0443 EVAP CANISTER PURGE VOLUME
CONTROL SOLENOID VALVE ......................
222
Description .............................................................222
On Board Diagnosis Logic .....................................222
DTC Confirmation Procedure ................................222
Diagnosis Procedure .............................................223
Component Inspection ...........................................225
P0444, P0445 EVAP CANISTER PURGE
VOLUME CONTROL SOLENOID VALVE ......
227
Description .............................................................227
On Board Diagnosis Logic .....................................227
DTC Confirmation Procedure ................................228
Diagnosis Procedure .............................................228
Component Inspection ...........................................229
P0447 EVAP CANISTER VENT CONTROL
VALVE .............................................................
230
Component Description .........................................230
On Board Diagnosis Logic .....................................230
DTC Confirmation Procedure ................................230
Diagnosis Procedure .............................................230
Component Inspection ...........................................232
P0448 EVAP CANISTER VENT CONTROL
VALVE .............................................................
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Component Description .........................................234
On Board Diagnosis Logic .....................................234
DTC Confirmation Procedure ................................234
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EC-4
Diagnosis Procedure .............................................235
Component Inspection ...........................................236
P0451 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
238
Component Description ....................................... ..238
On Board Diagnosis Logic .....................................238
DTC Confirmation Procedure ................................238
Diagnosis Procedure .............................................238
Component Inspection ...........................................239
P0452 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
241
Component Description ....................................... ..241
On Board Diagnosis Logic .....................................241
DTC Confirmation Procedure ................................241
Diagnosis Procedure .............................................242
Component Inspection ...........................................244
P0453 EVAP CONTROL SYSTEM PRES-
SURE SENSOR ...............................................
245
Component Description ....................................... ..245
On Board Diagnosis Logic .....................................245
DTC Confirmation Procedure ................................245
Diagnosis Procedure .............................................246
Component Inspection ...........................................249
P0455 EVAP CONTROL SYSTEM ..................250
On Board Diagnosis Logic ................................... ..250
DTC Confirmation Procedure ................................250
Diagnosis Procedure .............................................251
Component Inspection ...........................................256
P0456 EVAP CONTROL SYSTEM ..................257
On Board Diagnosis Logic ................................... ..257
DTC Confirmation Procedure ................................258
Overall Function Check .........................................258
Diagnosis Procedure .............................................259
Component Inspection ...........................................264
P0460 FUEL LEVEL SENSOR ........................265
Component Description ....................................... ..265
On Board Diagnosis Logic .....................................265
DTC Confirmation Procedure ................................265
Diagnosis Procedure .............................................265
P0461 FUEL LEVEL SENSOR ........................267
Component Description ....................................... ..267
On Board Diagnosis Logic .....................................267
Overall Function Check .........................................267
Diagnosis Procedure .............................................268
P0462, P0463 FUEL LEVEL SENSOR ...........269
Component Description ....................................... ..269
On Board Diagnosis Logic .....................................269
DTC Confirmation Procedure ................................269
Diagnosis Procedure .............................................269
P0500 VSS .......................................................271
Description ........................................................... ..271
On Board Diagnosis Logic .....................................271
DTC Confirmation Procedure ............................... .271
Overall Function Check .........................................272
Diagnosis Procedure .............................................272
P0506 ISC SYSTEM .........................................273
Description ........................................................... .273
On Board Diagnosis Logic ....................................273
DTC Confirmation Procedure ................................273
Diagnosis Procedure .............................................273
P0507 ISC SYSTEM .........................................275
Description ........................................................... .275
On Board Diagnosis Logic ....................................275
DTC Confirmation Procedure ................................275
Diagnosis Procedure .............................................275
P0550 PSP SENSOR .......................................277
Component Description ....................................... .277
On Board Diagnosis Logic ....................................277
DTC Confirmation Procedure ................................277
Diagnosis Procedure .............................................277
Component Inspection ..........................................279
P0603 ECM POWER SUPPLY .........................280
Description ........................................................... .280
DTC Logic .............................................................280
Diagnosis Procedure .............................................280
P0605 ECM .......................................................282
Component Description ....................................... .282
On Board Diagnosis Logic ....................................282
DTC Confirmation Procedure ................................282
Diagnosis Procedure .............................................283
P0607 ECM .......................................................284
Description ........................................................... .284
On Board Diagnosis Logic ....................................284
DTC Confirmation Procedure ................................284
Diagnosis Procedure .............................................284
P0643 SENSOR POWER SUPPLY ..................285
On Board Diagnosis Logic ...................................
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DTC Confirmation Procedure ................................285
Diagnosis Procedure .............................................285
P0850 PNP SWITCH ........................................288
Component Description ....................................... .288
On Board Diagnosis Logic ....................................288
DTC Confirmation Procedure ................................288
Overall Function Check .........................................288
Diagnosis Procedure .............................................289
P1140, P1145 IVT CONTROL POSITION
SENSOR ...........................................................
291
Component Description ....................................... .291
On Board Diagnosis Logic ....................................291
DTC Confirmation Procedure ................................291
Diagnosis Procedure .............................................291
Component Inspection ..........................................294
P1148, P1168 CLOSED LOOP CONTROL .....295
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EC-6
On Board Diagnosis Logic .....................................351
DTC Confirmation Procedure ................................351
Diagnosis Procedure .............................................351
P2101 ELECTRIC THROTTLE CONTROL
FUNCTION .......................................................
354
Description ........................................................... ..354
On Board Diagnosis Logic .....................................354
DTC Confirmation Procedure ................................354
Diagnosis Procedure .............................................354
Component Inspection ...........................................357
P2118 THROTTLE CONTROL MOTOR ..........358
Component Description ....................................... ..358
On Board Diagnosis Logic .....................................358
DTC Confirmation Procedure ................................358
Diagnosis Procedure .............................................358
Component Inspection ...........................................359
P2119 ELECTRIC THROTTLE CONTROL
ACTUATOR .....................................................
360
Component Description ....................................... ..360
On Board Diagnosis Logic .....................................360
DTC Confirmation Procedure ................................360
Diagnosis Procedure .............................................361
P2122, P2123 APP SENSOR ..........................362
Component Description ....................................... ..362
On Board Diagnosis Logic .....................................362
DTC Confirmation Procedure ................................362
Diagnosis Procedure .............................................362
Component Inspection ...........................................364
P2127, P2128 APP SENSOR ..........................365
Component Description ....................................... ..365
On Board Diagnosis Logic .....................................365
DTC Confirmation Procedure ................................365
Diagnosis Procedure .............................................365
Component Inspection ...........................................368
P2135 TP SENSOR .........................................369
Component Description ....................................... ..369
On Board Diagnosis Logic .....................................369
DTC Confirmation Procedure ................................369
Diagnosis Procedure .............................................369
Component Inspection ...........................................372
P2138 APP SENSOR ......................................373
Component Description ....................................... ..373
On Board Diagnosis Logic .....................................373
DTC Confirmation Procedure ................................373
Diagnosis Procedure .............................................374
Component Inspection ...........................................376
P2A00, P2A03 A/F SENSOR 1 .......................377
Component Description ....................................... ..377
On Board Diagnosis Logic .....................................377
DTC Confirmation Procedure ................................377
Diagnosis Procedure .............................................378
ASCD BRAKE SWITCH ................................. .383
Component Description ....................................... .383
Diagnosis Procedure .............................................383
Component Inspection ..........................................386
ASCD INDICATOR ...........................................387
Component Description ....................................... .387
Diagnosis Procedure .............................................387
COOLING FAN .................................................388
Diagnosis Procedure ............................................ .388
Component Inspection ..........................................388
ELECTRICAL LOAD SIGNAL ..........................390
Description ........................................................... .390
Diagnosis Procedure .............................................390
FUEL INJECTOR ..............................................392
Component Description ....................................... .392
Diagnosis Procedure .............................................392
Component Inspection ..........................................394
FUEL PUMP .....................................................395
Description ........................................................... .395
Diagnosis Procedure .............................................395
Component Inspection ..........................................398
ICC BRAKE SWITCH ..................................... ..399
Component Description ....................................... .399
Diagnosis Procedure .............................................399
Component Inspection ..........................................402
IGNITION SIGNAL ............................................404
Component Description ....................................... .404
Diagnosis Procedure .............................................404
Component Inspection ..........................................407
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) .....................................................
409
System Description .............................................. .409
Diagnosis Procedure .............................................409
Component Inspection ..........................................411
POSITIVE CRANKCASE VENTILATION .........414
Description ........................................................... .414
Component Inspection ..........................................414
REFRIGERANT PRESSURE SENSOR ...........416
Component Description ....................................... .416
Diagnosis Procedure .............................................416
ECU DIAGNOSIS ......................................419
ECM ................................................................ ..419
CONSULT-lll Reference Value in Data Monitor
Mode .................................................................... .
419
ECM Harness Connector Terminal Layout ...........422
ECM Terminal and Reference Value ....................422
Wiring Diagram - ENGINE CONTROL SYSTEM - .432
Fail-Safe Chart ......................................................453
DTC Inspection Priority Chart ...............................455
DTC Index .............................................................456
Emission-related Diagnostic Information ..............460
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EC-7
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SYMPTOM DIAGNOSIS ..... .......................475
ENGINE CONTROL SYSTEM SYMPTOMS .. ..475
Symptom Matrix Chart ........................................ ..475
NORMAL OPERATING CONDITION ...............479
Fuel Cut Control (at No Load and High Engine
Speed) ................................................................. ..
479
PRECAUTION ............................................480
PRECAUTIONS .............................................. ..480
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ..
480
On Board Diagnosis (OBD) System of Engine and
A/T .........................................................................
480
Precaution .............................................................481
PREPARATION .........................................484
PREPARATION .............................................. ..484
Special Service Tool ........................................... ..484
Commercial Service Tool ......................................485
ON-VEHICLE MAINTENANCE ..................487
FUEL PRESSURE .......................................... ..487
Fuel Pressure Check ........................................... ..487
EVAP LEAK CHECK ........................................489
How to Detect Fuel Vapor Leakage .................... ..489
ON-VEHICLE REPAIR ...............................491
EVAP CANISTER ............................................491
Removal and Installation ..................................... ..491
Component Inspection ...........................................491
INTAKE VALVE TIMING CONTROL ..............492
Intake Valve Timing Control Solenoid Valve (LH) ..492
Intake Valve Timing Cont rol Solenoid Valve (RH) ..492
Intake Valve Timing Control Position Sensor (LH) ..493
Intake Valve Timing Control Position Sensor (RH) ..493
Camshaft Position Sensor (PHASE) .....................493
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... ...........................................
495
SERVICE DATA AND SPECIFICATIONS
(SDS) ...............................................................
495
Fuel Pressure ...................................................... ..495
Idle Speed and Ignition Timing ..............................495
Calculated Load Value ..........................................495
Mass Air Flow Sensor ............................................495
Intake Air Temperature Sensor .............................495
Engine Coolant Temperature Sensor ....................495
A/F Sensor 1 Heater ..............................................495
Heated Oxygen sensor 2 Heater ...........................496
Crankshaft Position Sensor (POS) ........................496
Camshaft Position Sensor (PHASE) .....................496
Throttle Control Motor ............................................496
Fuel Injector ...........................................................496
Fuel Pump .............................................................496
Revision: December 20092009 QX56

EC-8
< BASIC INSPECTION >[VK56DE]
DIAGNOSIS AND REPAIR WORKFLOW
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Trouble Diagnosis IntroductionINFOID:0000000003771293
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-III (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 dr iveability 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 Di agnostic Worksheet like the example
on "Worksheet Sample" should be used.
Start your diagnosis by looking fo r conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
WORK FLOW
MEF036D
SEF233G
SEF234G
Revision: December 20092009 QX56

EC-10
< BASIC INSPECTION >[VK56DE]
DIAGNOSIS AND REPAIR WORKFLOW
2.CHECK DTC*1
1. Check DTC*1 .
2. Perform the following procedure if DTC*
1 is displayed.
- Record DTC*
1 and freeze frame data*2 . (Print them out with CONSULT-III or GST.)
- Erase DTC*
1 . (Refer to EC-456, "DTC Index" .)
- Study the relationship betw een the cause detected by DTC*
1 and the symptom described by the cus-
tomer. (Symptom Matrix Chart is useful. Refer to EC-475, "Symptom Matrix Chart"
.)
3. Check related service bulletins for information.
Is any symptom described and any DTC detected?
Symptom is described, DTC*1 is displayed>>GO TO 3.
Symptom is described, DTC*
1 is not displayed>>GO TO 4.
Symptom is not described, DTC*
1 is displayed>>GO TO 5.
3.CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer (except MIL ON).
DIAGNOSIS WORK SHEET is useful to verify the incident.
Connect CONSULT-III to the vehicle and check real time diagnosis results.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 5.
4.CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer.
DIAGNOSIS WORK SHEET is useful to verify the incident.
Connect CONSULT-III to the vehicle and check real time diagnosis results.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 6.
5.PERFORM DTC CONFIRMATION PROCEDURE
Perform DTC Confirmation Procedure for the displayed DTC* , and then make sure that DTC*
1 is detected
again.
If two or more DTCs*
1 are detected, refer to EC-455, "DTC Inspection Priority Chart" and determine trouble
diagnosis order.
NOTE:
• Freeze frame data*
2 is useful if the DTC*1 is not detected.
 Perform Overall Function Check if DTC Confirma tion Procedure is not included on Service Manual. This
simplified check procedure is an effective alternative though DTC*
1 cannot be detected during this check.
If the result of Overall Function Check is NG, it is the same as the detection of DTC*
1 by DTC Confirmation
Procedure.
Is DTC*
1 detected?
Yes >> GO TO 10.
No >> Check according to GI-38, "Intermittent Incident"
.
6.PERFORM BASIC INSPECTION
Perform EC-13, "Basic Inspection"
.
With CONSULT-III>>GO TO 7.
Without CONSULT-III>>GO TO 9.
7.PERFORM SPEC IN DATA MONITOR MODE
With CONSULT-III
Make sure that “MAS A/F SE-B1”, “B/FUEL SCHDL”, and “A/F ALPHA-B1”, “A/F ALPHA-B2” are within the SP
value using CONSULT-III “SPEC” in “DATA MONITOR” mode. Refer to EC-74
.
Revision: December 20092009 QX56