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EC-6
Component Description .........................................359
On Board Diagnosis Logic .....................................359
DTC Confirmation Procedure ................................359
Diagnosis Procedure .............................................360
P2101 ELECTRIC THROTTLE CONTROL
FUNCTION .......................................................
362
Description ........................................................... ..362
On Board Diagnosis Logic .....................................362
DTC Confirmation Procedure ................................362
Diagnosis Procedure .............................................362
Component Inspection ...........................................365
P2118 THROTTLE CONTROL MOTOR ..........366
Component Description ....................................... ..366
On Board Diagnosis Logic .....................................366
DTC Confirmation Procedure ................................366
Diagnosis Procedure .............................................366
Component Inspection ...........................................367
P2119 ELECTRIC THROTTLE CONTROL
ACTUATOR .....................................................
368
Component Description ....................................... ..368
On Board Diagnosis Logic .....................................368
DTC Confirmation Procedure ................................368
Diagnosis Procedure .............................................369
P2122, P2123 APP SENSOR ..........................370
Component Description ....................................... ..370
On Board Diagnosis Logic .....................................370
DTC Confirmation Procedure ................................370
Diagnosis Procedure .............................................371
Component Inspection ...........................................372
P2127, P2128 APP SENSOR ..........................373
Component Description ....................................... ..373
On Board Diagnosis Logic .....................................373
DTC Confirmation Procedure ................................373
Diagnosis Procedure .............................................373
Component Inspection ...........................................376
P2135 TP SENSOR .........................................377
Component Description ....................................... ..377
On Board Diagnosis Logic .....................................377
DTC Confirmation Procedure ................................377
Diagnosis Procedure .............................................377
Component Inspection ...........................................380
P2138 APP SENSOR ......................................381
Component Description ....................................... ..381
On Board Diagnosis Logic .....................................381
DTC Confirmation Procedure ................................381
Diagnosis Procedure .............................................382
Component Inspection ...........................................384
P2A00, P2A03 A/F SENSOR 1 .......................385
Component Description ....................................... ..385
On Board Diagnosis Logic .....................................385
DTC Confirmation Procedure ................................385
Diagnosis Procedure .............................................386
ASCD BRAKE SWITCH ...................................390
Component Description ....................................... .390
Diagnosis Procedure .............................................390
Component Inspection ..........................................393
ASCD INDICATOR ...........................................394
Component Description ....................................... .394
Diagnosis Procedure .............................................394
COOLING FAN .................................................395
Diagnosis Procedure ............................................ .395
Component Inspection ..........................................395
ELECTRICAL LOAD SIGNAL ..........................397
Description ........................................................... .397
Diagnosis Procedure .............................................397
FUEL INJECTOR ..............................................399
Component Description ....................................... .399
Diagnosis Procedure .............................................399
Component Inspection ..........................................401
FUEL PUMP .....................................................402
Description ........................................................... .402
Diagnosis Procedure .............................................402
Component Inspection ..........................................405
ICC BRAKE SWITCH ..................................... ..406
Component Description ....................................... .406
Diagnosis Procedure .............................................406
Component Inspection ..........................................409
IGNITION SIGNAL ............................................411
Component Description ....................................... .411
Diagnosis Procedure .............................................411
Component Inspection ..........................................414
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) .....................................................
416
System Description .............................................. .416
Diagnosis Procedure .............................................416
Component Inspection ..........................................418
POSITIVE CRANKCASE VENTILATION .........421
Description ........................................................... .421
Component Inspection ..........................................421
REFRIGERANT PRESSURE SENSOR ...........423
Component Description ....................................... .423
Diagnosis Procedure .............................................423
ECU DIAGNOSIS ......................................426
ECM ................................................................ ..426
CONSULT-lll Reference Value in Data Monitor
Mode .................................................................... .
426
ECM Harness Connector Terminal Layout ...........429
ECM Terminal and Reference Value ....................429
Wiring Diagram - ENGINE CONTROL SYSTEM - .439
Fail-Safe Chart ......................................................459
DTC Inspection Priority Chart ...............................461
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DTC Index ...........................................................
..
462
Emission-related Diagnostic Information ...............466
SYMPTOM DIAGNOSIS ..... .......................481
ENGINE CONTROL SYSTEM SYMPTOMS .. ..481
Symptom Matrix Chart ........................................ ..481
NORMAL OPERATING CONDITION ...............485
Fuel Cut Control (at No Load and High Engine
Speed) ................................................................. ..
485
PRECAUTION ............................................486
PRECAUTIONS .............................................. ..486
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ..
486
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ..
486
On Board Diagnosis (OBD) System of Engine and
A/T .........................................................................
487
Precaution .............................................................487
PREPARATION .........................................491
PREPARATION .............................................. ..491
Special Service Tool ........................................... ..491
Commercial Service Tool ......................................492
ON-VEHICLE MAINTENANCE ..................494
FUEL PRESSURE .......................................... ..494
Fuel Pressure Check .............................................494
EVAP LEAK CHECK ......................................496
How to Detect Fuel Vapor Leakage ..................... ..496
ON-VEHICLE REPAIR ...............................498
EVAP CANISTER ............................................498
Component Inspection ......................................... ..498
Removal and Installation .......................................498
INTAKE VALVE TIMING CONTROL ..............500
Intake Valve Timing Control Solenoid Valve (LH) ..500
Intake Valve Timing Cont rol Solenoid Valve (RH) ..500
Intake Valve Timing Control Position Sensor (LH) ..501
Intake Valve Timing Control Position Sensor (RH) ..501
Camshaft Position Sensor (PHASE) .....................501
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... .
503
SERVICE DATA AND SPECIFICATIONS
(SDS) ...............................................................
503
Fuel Pressure ...................................................... ..503
Idle Speed and Ignition Timing ..............................503
Calculated Load Value ..........................................503
Mass Air Flow Sensor ............................................503
Intake Air Temperature Sensor .............................503
Engine Coolant Temperature Sensor ....................503
A/F Sensor 1 Heater ..............................................503
Heated Oxygen sensor 2 Heater ...........................504
Crankshaft Position Sensor (POS) ........................504
Camshaft Position Sensor (PHASE) .....................504
Throttle Control Motor ............................................504
Fuel Injector ...........................................................504
Fuel Pump .............................................................504
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![INFINITI QX56 2008 Factory Service Manual EC-8
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BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Trouble Diagnosis IntroductionINFOID:0000000001351337
INTRODUCTION
The engine has an ECM INFINITI QX56 2008 Factory Service Manual EC-8
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BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Trouble Diagnosis IntroductionINFOID:0000000001351337
INTRODUCTION
The engine has an ECM](/manual-img/42/57030/w960_57030-1306.png)
EC-8
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DIAGNOSIS AND REPAIR WORKFLOW
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Trouble Diagnosis IntroductionINFOID:0000000001351337
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 driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A 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
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Overall Sequence
Detailed Flow
1.GET INFORMATION FOR SYMPTOM
Get the detailed information from the customer about the symptom (the condition and the environment when
the incident/malfunction occurred) using the "Worksheet Sample" .
>> GO TO 2.
PBIB3456E
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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 . ( INFINITI QX56 2008 Factory Service Manual 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 . (](/manual-img/42/57030/w960_57030-1308.png)
EC-10
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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-462, "DTC Index" .)
- Study the relationship between the cause detected by DTC*
1 and the symptom described by the cus-
tomer. (Symptom Matrix Chart is useful. Refer to EC-481, "
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-461, "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-75
.
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Are they within the SP value?
Yes >> GO TO 9.
No >> GO TO 8.
8.DETECT MALFUNCTIONING PART BY TROUBLE DI INFINITI QX56 2008 Factory Service Manual DIAGNOSIS AND REPAIR WORKFLOWEC-11
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Are they within the SP value?
Yes >> GO TO 9.
No >> GO TO 8.
8.DETECT MALFUNCTIONING PART BY TROUBLE DI](/manual-img/42/57030/w960_57030-1309.png)
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Are they within the SP value?
Yes >> GO TO 9.
No >> GO TO 8.
8.DETECT MALFUNCTIONING PART BY TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Detect malfunctioning part according to EC-76, "
Diagnosis Procedure".
Is malfunctioning part detected?
Yes >> GO TO 11.
No >> GO TO 9.
9.DETECT MALFUNCTIONING SYST EM BY SYMPTOM MATRIX CHART
Detect malfunctioning system according to EC-481, "
Symptom Matrix Chart" based on the confirmed symp-
tom in step 4, and determine the trouble diagnosis order based on possible causes and symptom.
>> GO TO 10.
10.DETECT MALFUNCTIONING PART BY DIAGNOSTIC PROCEDURE
Inspect according to Diagnostic Procedure of the system.
NOTE:
The Diagnostic Procedure in EC section described based on open circuit inspection. A short circuit inspection
is also required for the circuit check in the Diagnostic Procedure. For details, refer to Circuit Inspection in GI-
34, "Work Flow".
Is malfunctioning part detected?
Yes >> GO TO 11.
No >> Monitor input data from related sensors or check voltage of related ECM terminals using CON- SULT-III. Refer to EC-429, "
ECM Terminal and Reference Value", EC-426, "CONSULT-lll Refer-
ence Value in Data Monitor Mode".
11 .REPAIR OR REPLACE THE MALFUNCTIONING PART
1. Repair or replace the malfunctioning part.
2. Reconnect parts or connectors disconnected during Diagnostic Procedure again after repair and replace-
ment.
3. Check DTC. If DTC is displayed, erase it, refer to EC-462, "
DTC Index".
>> GO TO 12.
12.FINAL CHECK
When DTC was detected in step 2, perform DTC Confirmation Procedure or Overall Function Check again,
and then make sure that the malfunction have been repaired securely.
When symptom was described from the customer, refer to confirmed symptom in step 3 or 4, and make sure
that the symptom is not detected.
OK or NG
NG (DTC*1 is detected)>>GO TO 10.
NG (Symptom remains)>>GO TO 6.
OK >> 1. Before returning the vehicle to the cu stomer, make sure to erase unnecessary DTC*
1 in ECM
and TCM (Transmission Control Module). (Refer to EC-462, "
DTC Index" and TM-30, "OBD-
II Diagnostic Trouble Code (DTC)".)
2. If the completion of SRT is needed, drive vehicle under the specific driving pattern. Refer to EC-462, "
DTC Index".
3. INSPECTION END
*1: Include 1st trip DTC.
*2: Include 1st trip freeze frame data.
DIAGNOSTIC WORKSHEET
Description
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EC-12
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DIAGNOSIS AND REPAIR WORKFLOW
There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about a incident. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MIL to come on steady or blink and
DTC to be detected. Examples:
• Vehicle ran out of fuel, which caused the engine to misfire.
• Fuel filler cap was left off or incorrectly screwed on, allowing fuel to
evaporate into the atmosphere.
Worksheet Sample
SEF907L
MTBL0017
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Basic InspectionINFOID:0000000001351329
1.INSPECTION START
1. Check service recor INFINITI QX56 2008 Factory Service Manual INSPECTION AND ADJUSTMENTEC-13
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1. Check service recor](/manual-img/42/57030/w960_57030-1311.png)
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INSPECTION AND ADJUSTMENT
Basic InspectionINFOID:0000000001351329
1.INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for scheduled maintenance.
2. Open engine hood and check the following:
- Harness connectors for improper connections
- Wiring harness for improper connections, pinches and cut
- Vacuum hoses for splits, kinks and improper connections
- Hoses and ducts for leaks
- Air cleaner clogging
- Gasket
3. Confirm that electrical or mechanical loads are not applied.
- Headlamp switch is OFF.
- Air conditioner switch is OFF.
- Rear window defogger switch is OFF.
- Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no load.
6. Make sure that no DTC is displayed with CONSULT-III or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
3.CHECK TARGET IDLE SPEED
With CONSULT-III
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
SEF983U
SEF976U
SEF977U
Revision: March 2010 2008 QX56