OBD port INFINITI QX56 2008 Factory Service Manual

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 .........................75
TROUBLE DIAGNOSIS - SPECIFICATION
VALUE ...............................................................
75
Description ........................................................... ....75
Testing Condition .....................................................75
Inspection Procedure ...............................................75
Diagnosis Procedure ...............................................76
POWER SUPPLY AND GROUND CIRCUIT ....83
Diagnosis Procedure ...............................................83
Ground Inspection ...................................................86
U1000, U1001 CAN COMM CIRCUIT ...............87
Description ...............................................................87
On Board Diagnosis Logic .......................................87
DTC Confirmation Procedure ..................................87
Diagnosis Procedure ...............................................87
U1010 CONTROL UNIT (CAN) .........................88
Description ...............................................................88
On Board Diagnosis Logic .......................................88
DTC Confirmation Procedure ..................................88
Diagnosis Procedure ...............................................88
P0011, P0021 IVT CONTROL ...........................90
On Board Diagnosis Logic .......................................90
Revision: March 2010 2008 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-43
< FUNCTION DIAGNOSIS > [VK56DE]
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Data which are stored in the ECM memory, along with the
1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are ca lled freeze frame data and displayed on CONSULT-III or
GST. The 1st trip freeze frame dat a can only be displayed on the CONSULT-III screen, not on the GST. For
details, see EC-63, "
CONSULT-III Function (ENGINE)".
Only one set of freeze frame data (either 1st trip freez e frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM me mory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
For example, the EGR malfunction (Priority: 2) was detected and the fr eeze frame data was stored in the 2nd
trip. After that when the misfire (Priority: 1) is detected in another trip, the freeze frame data will be updated
from the EGR malfunction to the misfire. The 1st trip freeze frame data is updated each time a different mal-
function is detected. There is no priority for 1st tr ip freeze frame data. However, once freeze frame data is
stored in the ECM memory, 1st trip freeze data is no longer stored (because only one freeze frame data or 1st
trip freeze frame data can be stored in the ECM). If freeze frame data is stored in the ECM memory and freeze
frame data with the same priority occurs later, the first (original) freeze frame data remains unchanged in the
ECM memory.
Both 1st trip freeze frame data and freeze frame dat a (along with the DTCs) are cleared when the ECM mem-
ory is erased. Procedures for clearing the ECM memory are described in "HOW TO ERASE EMISSION-
RELATED DIAGNOSTIC INFORMATION".
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Service $01 of SAE J1979.
As part of an enhanced emissions test for Inspection & Ma intenance (I/M), certain states require the status of
SRT be used to indicate whether the ECM has comple ted self-diagnosis of major emission systems and com-
ponents. Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspection due to one or more SRT items indicating “INCMP”, use
the information in this Service Manual to set the SRT to “CMPLT”.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate “CMPLT” for each application system. Once set as “CMPLT”, the SRT status remains
“CMPLT” until the self-diagnosis memory is erased.
Occasionally, certain portions of the self-diagnostic test may not be completed as a result of the customer's
normal driving pattern; the SRT will indicate “INCMP” for these items.
NOTE:
The SRT will also indicate “INCMP” if the self-diagnosis memory is erased for any reason or if the ECM mem-
ory power supply is interrupted for several hours.
If, during the state emissions inspection, the SRT indicates “CMPLT” for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT i ndicates “INCMP” for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
If MIL is ON during the state emissi ons inspection, the vehicle is also returned to the customer untested even
though the SRT indicates “CMPLT” for all test items. T herefore, it is important to check SRT (“CMPLT”) and
DTC (No DTCs) before the inspection.
SRT Item
The table below shows required self-diagnostic items to set the SRT to “CMPLT”.
Priority Items
1 Freeze frame data Misfire — DTC: P0300 - P0308
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
SRT item
(CONSULT-III indication) Performance
Priority* Required self-diagnostic items to set the SRT to “CMPLT”
Corresponding
DTC No.
CATALYST 2 Three way catalyst function P0420, P0430
Revision: March 2010 2008 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-63
< FUNCTION DIAGNOSIS > [VK56DE]
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• The A counter will be cleared when the malfunction is detected regardless of (1) - (4).
• The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.
• The DTC will not be displayed after the A counter reaches 40.

Driving pattern B means the vehicle operation as follows:
All components and systems should be monitored at least once by the OBD system.
• The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.
• The B counter will be counted up when driving pattern B is satisfied without any malfunctions.
• The MIL will go off when the B counter reac
hes 3 (*2 in OBD SYSTEM OPERATION CHART).
CONSULT-III Function (ENGINE)INFOID:0000000001351348
FUNCTION
*: The following emission-related diagnostic information is cleared when the ECM memory is erased.
• Diagnostic trouble codes
• 1st trip diagnostic trouble codes
• Freeze frame data
• 1st trip freeze frame data
• System readiness test (SRT) codes
•Test values
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
AEC574
Diagnostic test mode Function
Work support This mode enables a technician to adjust some devices faster and more accurately by following the in-
dications on the CONSULT-III unit.
Self-diagnostic results Self-diagnostic results such as 1st trip DTC, DTCs and 1st trip freeze frame data or freeze frame data
can be read and erased quickly.*
Data monitor Input/Output data in the ECM can be read.
Active test Diagnostic Test Mode in which CONSULT-III drives some actuators apart from the ECMs and also shifts
some parameters in
a specified range.
Function test This mode is used to inform customers when their vehicle condition requires periodic maintenance.
DTC & SRT confirmation The status of system monitoring tests and the self-diagnosis status/result can be confirmed.
ECU Identification ECM part number can be read.
Revision: March 2010 2008 QX56

EC-64
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
ItemDIAGNOSTIC TEST MODE
WORK SUP-
PORT SELF-DIAGNOSTIC
RESULTS DATA
MONI-
TOR ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT
STATUS DTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS) ×××
Camshaft position sensor (PHASE) ×××
Mass air flow sensor ××
Engine coolant temperature sensor ××××
Air fuel ratio (A/F) sensor 1 ××× ×
Heated oxygen sensor 2 ××× ×
Wheel sensor ×××
Accelerator pedal position sensor ××
Throttle position sensor ×××
Fuel tank temperature sensor ×××
EVAP control system pressure sen-
sor ××
Intake air temperature sensor ×××
Knock sensor ×
Refrigerant pressure sensor ×
Closed throttle position switch (ac-
celerator pedal position sensor sig-
nal) ×
Air conditioner switch ×
Park/neutral position (PNP) signal ××
Stop lamp switch ××
Power steering pressure sensor ××
Battery voltage ×
Load signal ×
Intake valve timing control position
sensor ××
Fuel level sensor ××
Battery current sensor ××
ICC steering switch ××
ASCD steering switch ××
ICC brake switch ××
ASCD brake switch ××
Revision: March 2010 2008 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-65
< FUNCTION DIAGNOSIS > [VK56DE]
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X: Applicable
*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze frame data. The items appear on CONSULT-III screen in freeze frame
data
mode only if a 1st trip DTC or DTC is detected. For details, refer to "Freeze Frame Data and 1st Trip Freeze Frame Data".
*3: Always “CMPLT ” is displayed.
WORK SUPPORT MODE
Work Item
ENGINE CONTROL COMPONENT PARTS
OUTPUT
Fuel injector ××
Power transistor (Ignition timing) ××
Throttle contro l motor relay ××
Throttle control motor ×
EVAP canister purge volume con-
trol solenoid valve ××
××
Air conditioner relay ×
Fuel pump relay ×× ×
Cooling fan relay ×××
Air fuel ratio (A/F) sensor 1 heater ×××*3
Heated oxygen sensor 2 heater ×××*3
EVAP canister vent control valve ×× ××
Intake valve timing control solenoid
valve ××
×
Alternator ××
Calculated load value ××
Item
DIAGNOSTIC TEST MODE
WORK SUP-
PORT SELF-DIAGNOSTIC
RESULTS DATA
MONI- TOR ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT
STATUS DTC
WORK SUP-
PORT
WORK ITEM CONDITION USAGE
FUEL PRESSURE RELEASE • FUEL PUMP WILL STOP BY TOUCHING “START” DUR- ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS. When releasing fuel pressure from
fuel line
IDLE AIR VOL LEARN • THE IDLE AIR VOLUME THAT KEEPS THE ENGINE
WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM. When learning the idle air volume
SELF-LEARNING CONT • THE COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT. When clearing the coefficient of
self-learning control value
Revision: March 2010
2008 QX56

EC-72
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: Leaving cooling fan OFF with CONSULT-III while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-462, "DTC Index".
SRT WORK SUPPORT Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
DTC WORK SUPPORT Mode
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.
Generic Scan Tool (GST) FunctionINFOID:0000000001351349
DESCRIPTION
PURG VOL
CONT/V• Engine: After warming up, run en-
gine at 1,500 rpm.
• Change the EVAP canister purge volume control solenoid valve
opening percent using CON-
SULT-III. Engine speed changes according to
the opening percent.
• Harness and connectors
• Solenoid valve
FUEL/T TEMP
SEN • Change the fuel tank temperature using CONSULT-III.
VENT CON-
TROL/V • Ignition switch: ON
(Engine stopped)
• Turn solenoid valve ON and OFF with the CONSULT-III and listen
to operating sound. Solenoid valve makes an operating
sound.
• Harness and connectors
• Solenoid valve
V/T ASSIGN AN-
GLE • Engine: Return to the original
trouble condition
• Change intake valve timing using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
• Harness and connectors
• Intake valve timing control sole-
noid valve
ALTERNATOR
DUTY •Engine: Idle
• Change duty ratio using CON-
SULT-III. Battery voltage changes. • Harness and connectors
• IPDM E/R
•Alternator
TEST ITEM
CONDITION JUDGEMENTCHECK ITEM (REMEDY)
Test mode Test itemCorresponding DTC No. Reference page
EVAPORATIVE
SYSTEM PURG FLOW P0441
P0441EC-219
EVP SML LEAK P0442/P1442* P0442
EC-224P0455EC-259
EVP V/S LEAK P0456/P1456* P0456EC-266
PURG VOL CN/V P1444 P0443EC-231
A/F SEN1 A/F SEN1 (B1) P1276
P0130EC-141A/F SEN1 (B1) P1278/P1279 P0133EC-153
A/F SEN1 (B2) P1286 P0150EC-141
A/F SEN1 (B2) P1288/P1289 P0153EC-153
HO2S2 HO2S2 (B1) P0139
P0139EC-171
HO2S2 (B1) P1146 P0138EC-164
HO2S2 (B1) P1147 P0137EC-159
HO2S2 (B2) P0159 P0159EC-171
HO2S2 (B2) P1166 P0158EC-164
HO2S2 (B2) P1167 P0157EC-159
Revision: March 2010 2008 QX56

EC-492
< PREPARATION >[VK56DE]
PREPARATION
Commercial Service Tool
INFOID:0000000001351225
(J-45488)
Quick connector re-
lease Remove fuel tube quick connectors in engine
room.
(J-23688)
Engine coolant refrac-
tometer Checking concentration of ethylene glycol in en-
gine coolant
Tool number
(Kent-Moore No.)
Tool name
Description
PBIC0198E
WBIA0539E
Tool name
(Kent-Moore No.)
Description
Leak detector
i.e.: (J-41416) Locating the EVAP leak
EVAP service port
adapter
i.e.: (J-41413-OBD) Applying positive pressure through EVAP service
port
Fuel filler cap adapter
i.e.: (MLR-8382) Checking fuel tank vacuum relief valve opening
pressure
Socket wrench Removing and installing engine coolant tempera-
ture sensor
S-NT703
S-NT704
S-NT815
S-NT705
Revision: March 2010 2008 QX56

GI-18
< HOW TO USE THIS MANUAL >
TERMINOLOGY
Nonvolatile random access memory NVRAM***
On board diagnostic system OBD system Self-diagnosis
Open loop OL Open loop
Oxidation catalyst OC Catalyst
Oxidation catalytic converter system OC system ***
Oxygen sensor O2S Exhaust gas sensor
Park position switch *** Park switch
Transmission range switch *** Park/neutral switch
Inhibitor switch
Neutral position switch
Periodic trap oxidizer system PTOX system ***
Positive crankcase ventilation PCV Positive crankcase ventilation
Positive crankcase ventilation valve PCV valve PCV valve
Powertrain cont rol module PCM ***
Programmable read only memory PROM ***
Pulsed secondary air injection control sole-
noid valve PAIRC solenoid valve
AIV control solenoid valve
Pulsed secondary air injection system PAIR system Air induction valve (AIV) control
Pulsed secondary air injection valve PAIR valve Air induction valve
Random access memory RAM ***
Read only memory ROM ***
Scan tool ST ***
Secondary air injection pump AIR pump***
Secondary air injection system AIR system ***
Sequential multiport fuel injection system SFI system Sequential fuel injection
Service reminder indicator SRI***
Simultaneous multiport fuel injection sys-
tem ***
Simultaneous fuel injection
Smoke puff limiter system SPL system ***
Supercharger SC ***
Supercharger bypass SCB ***
System readiness test SRT ***
Thermal vacuum valve TVVThermal vacuum valve
Three way catalyst TWCCatalyst
Three way catalytic converter system TWC system ***
Three way + oxidation catalyst TWC + OCCatalyst
Three way + oxidation catalytic converter
system TWC + OC system
***
Throttle body TB Throttle chamber
SPI body
Throttle body fuel injection system TBI system Fuel injection control
Throttle position TP Throttle position
Throttle position sensor TPS Throttle sensor
Throttle position switch TP switch Throttle switch
Torque converter clutch solenoid valve TCC solenoid valve Lock-up cancel solenoid
Lock-up solenoid
NEW TERM
NEW ACRONYM /
ABBREVIATION OLD TERM
Revision: March 2010
2008 QX56

LAN-10
< FUNCTION DIAGNOSIS >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Self-Diagnosis
INFOID:0000000001374968
CAN Diagnostic Support MonitorINFOID:0000000001374969
CONSULT-III and CAN diagnostic support monitor (on-boar d diagnosis function) are used for detecting root
cause.
MONITOR ITEM (CONSULT-III)
Unit name Symptom
ECM • Engine torque limiting is affected, and shift harshness increases.
• Engine speed drops.
BCM • Reverse warning chime does not sound.
• The front wiper moves under continuous operation mode even though the front
wiper switch being in the intermittent position.
• The room lamp does not turn ON.
• The engine does not start (if an error or malfunction occurs while turning the igni- tion switch OFF.)
• The steering lock does not release (if an error or malfunction occurs while turning the ignition switch OFF.)
EPS control unit The steering effort increases.
Combination meter • The tachometer and the speedometer do not move.
• Warning lamps turn ON.
• Indicator lamps do not turn ON.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/R When the ignition switch is ON,
• The headlamps (Lo) turn ON.
• The cooling fan continues to rotate.
DTC
Self-diagnosis item
(CONSULT-III indication) DTC detection condition
Inspection/Action
U1000 CAN COMM CIRCUIT When ECM is not transmitting or receiving CAN
communication signal of OBD (emission-related
diagnosis) for 2 seconds or more.
Refer to LAN-13
.
When a control unit (except for ECM) is not
transmitting or receiving CAN communication
signal for 2 seconds or more.
U1001 CAN COMM CIRCUIT When ECM is not transmitting or receiving CAN
communication signal other than OBD (emis-
sion-related diagnosis) for 2 seconds or more.
U1002 SYSTEM COMM When a control unit is not transmitting or receiv-
ing CAN communication signal for 2 seconds or
less. Start the inspection. Re-
fer to the applicable sec-
tion of the indicated
control unit.
U1010 CONTROL UNIT [CAN] When an error is detected during the initial diag-
nosis for CAN controller of each control unit. Replace the control unit
indicating “U1010”.
Revision: March 2010
2008 QX56

LAN
TROUBLE DIAGNOSISLAN-51
< FUNCTION DIAGNOSIS > [CAN]
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Never replace the unit even when “NG” is indicated on the “INITIAL DIAG” at this stage. Fo
llow the trouble diagnosis proce-
dures.
IPDM E/R
0: Error at present, 1 – 39: Error in the past (Number means the number of times the ignition switch is turned OFF→ ON)
*: 39 or higher number is fixed at 39 until the self-diagnosis result is erased.
DTC IndexINFOID:0000000001282403
ITEMCAN DIAG SUP-
PORT MNTR Description Normal
Error
PRSNT PAST PRSNT PAST
IPDM-E TRANSMIT DIAG Signal transmission status
OKOK
or
1 – 39
*UNKWN 0
ECM Signal receiving status from the ECM
BCM/SEC Signal receiving status from the BCM
DTC Self-diagnosis item
(CONSULT-III indication) DTC detection condition
Inspection
U1000 CAN COMM CIRCUIT When ECM is not transmitting or receiving CAN com-
munication signal of OBD (emission-related diagnosis)
for 2 seconds or more.
Refer to LAN-36
.
When a control unit (except for ECM) is not transmitting
or receiving CAN communication signal for 2 seconds
or more.
U1001 CAN COMM CIRCUIT When ECM is not transmitting or receiving CAN com-
munication signal other than OBD (emission-related di-
agnosis) for 2 seconds or more.
U1002 SYSTEM COMM When a control unit is not transmitting or receiving CAN
communication signal for 2 seconds or less. Start the inspection. Refer
to the applicable section
of the indicated control
unit.
U1010 CONTROL UNIT [CAN] When an error is detected during the initial diagnosis for
CAN controller of each control unit. Replace the control unit
indicating “U1010”.
Revision: March 2010
2008 QX56