2006 INFINITI FX35 engine control system

EC-8Revision: 2006 December 2006 FX35/FX45
PREPARATION ......................................................
.688
Special Service Tools .......................................... .688
Commercial Service Tools ................................... .689
ENGINE CONTROL SYSTEM ............................... .690
System Diagram .................................................. .690
Multiport Fuel Injection (MFI) System .................. .691
Electronic Ignition (EI) System ............................ .693
Fuel Cut Control (at No Load and High Engine
Speed) ................................................................. .694
AIR CONDITIONING CUT CONTROL ................... .695
Input/Output Signal Chart .................................... .695
System Description .............................................. .695
AUTOMATIC SPEED CONTROL DEVICE (ASCD) .696
System Description .............................................. .696
Component Description ....................................... .697
CAN COMMUNICATION ........................................ .698
System Description .............................................. .698
EVAPORATIVE EMISSION SYSTEM .................... .699
Description ........................................................... .699
Component Inspection ......................................... .702
Removal and Installation ..................................... .703
How to Detect Fuel Vapor Leakage ..................... .703
ON BOARD REFUELING VAPOR RECOVERY
(ORVR) ................................................................... .706
System Description .............................................. .706
Diagnostic Procedure .......................................... .707
Component Inspection ......................................... .709
POSITIVE CRANKCASE VENTILATION .............. .711
Description ........................................................... .711
Component Inspection ......................................... .711
IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-
NATS) ..................................................................... .713
Description ........................................................... .713
ON BOARD DIAGNOSTIC (OBD) SYSTEM ......... .714
Introduction .......................................................... .714
Two Trip Detection Logic ..................................... .714
Emission-related Diagnostic Information ............. .715
Malfunction Indicator Lamp (MIL) ........................ .729
OBD System Operation Chart ............................. .731
BASIC SERVICE PROCEDURE ............................ .737
Basic Inspection .................................................. .737
Idle Speed and Ignition Timing Check ................. .742
VIN Registration .................................................. .743
Accelerator Pedal Released Position Learning ... .743
Throttle Valve Closed Position Learning .............. .744
Idle Air Volume Learning ..................................... .744
Fuel Pressure Check ........................................... .746
TROUBLE DIAGNOSIS ......................................... .748
Trouble Diagnosis Introduction ............................ .748
DTC Inspection Priority Chart .............................. .754
Fail-Safe Chart .................................................... .756
Symptom Matrix Chart ......................................... .757
Engine Control Component Parts Location ......... .761
Vacuum Hose Drawing ........................................ .768
Circuit Diagram .................................................... .769
ECM Harness Connector Terminal Layout .......... .771
ECM Terminals and Reference Value .................. .771
CONSULT-II Function (ENGINE) ......................... .780
Generic Scan Tool (GST) Function ...................... .792 CONSULT-II Reference Value in Data Monitor ....
.795
Major Sensor Reference Graph in Data Monitor
Mode .................................................................... .799
TROUBLE DIAGNOSIS - SPECIFICATION VALUE .801
Description ........................................................... .801
Testing Condition ................................................. .801
Inspection Procedure ........................................... .801
Diagnostic Procedure ........................................... .802
TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT ...................................................................... .811
Description ........................................................... .811
Diagnostic Procedure ........................................... .811
POWER SUPPLY AND GROUND CIRCUIT .......... .812
Wiring Diagram .................................................... .812
Diagnostic Procedure ........................................... .813
Ground Inspection ................................................ .818
DTC U1000, U1001 CAN COMMUNICATION LINE .819
Description ........................................................... .819
On Board Diagnosis Logic ................................... .819
DTC Confirmation Procedure ............................... .819
Wiring Diagram .................................................... .820
Diagnostic Procedure ........................................... .821
DTC U1010 CAN COMMUNICATION .................... .822
Description ........................................................... .822
On Board Diagnosis Logic ................................... .822
DTC Confirmation Procedure ............................... .822
Diagnostic Procedure ........................................... .823
DTC P0011, P0021 IVT CONTROL ........................ .824
Description ........................................................... .824
CONSULT-II Reference Value in Data Monitor Mode .825
On Board Diagnosis Logic ................................... .825
DTC Confirmation Procedure ............................... .826
Wiring Diagram .................................................... .827
Diagnostic Procedure ........................................... .830
Component Inspection ......................................... .834
Removal and Installation ...................................... .835
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1
HEATER .................................................................. .836
Description ........................................................... .836
CONSULT-II Reference Value in Data Monitor Mode .836
On Board Diagnosis Logic ................................... .836
DTC Confirmation Procedure ............................... .836
Wiring Diagram .................................................... .837
Diagnostic Procedure ........................................... .840
Component Inspection ......................................... .842
Removal and Installation ...................................... .842
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER .843
Description ........................................................... .843
CONSULT-II Reference Value in Data Monitor Mode .843
On Board Diagnosis Logic ................................... .843
DTC Confirmation Procedure ............................... .844
Wiring Diagram .................................................... .845
Diagnostic Procedure ........................................... .848
Component Inspection ......................................... .850
Removal and Installation ...................................... .850
DTC P0075, P0081 IVT CONTROL SOLENOID

EC-14Revision: 2006 December 2006 FX35/FX45 CONSULT-II Reference Value in Data Monitor Mode
1295
Wiring Diagram .................................................... 1296
Diagnostic Procedure .......................................... 1297
Component Inspection ......................................... 1301
ASCD INDICATOR ................................................. 1302
Component Description ....................................... 1302
CONSULT-II Reference Value in Data Monitor Mode 1302
Wiring Diagram .................................................... 1303
Diagnostic Procedure .......................................... 1304
ELECTRICAL LOAD SIGNAL ............................... 1305
Description ........................................................... 1305
CONSULT-II Reference Value in Data Monitor Mode 1305
Diagnostic Procedure .......................................... 1305
FUEL INJECTOR ................................................... 1307
Component Description ....................................... 1307
CONSULT-II Reference Value in Data Monitor Mode 1307
Wiring Diagram .................................................... 1308
Diagnostic Procedure .......................................... 1309
Component Inspection ......................................... 1313
Removal and Installation ..................................... 1313
FUEL PUMP ........................................................... 1314
Description ........................................................... 1314
CONSULT-II Reference Value in Data Monitor Mode 1314
Wiring Diagram .................................................... 1315
Diagnostic Procedure .......................................... 1316
Component Inspection ......................................... 1319
Removal and Installation ..................................... 1319
ICC BRAKE SWITCH ............................................. 1320
Component Description ....................................... 1320
CONSULT-II Reference Value in Data Monitor Mode 1320
Wiring Diagram .................................................... 1321
Diagnostic Procedure .......................................... 1322
Component Inspection ......................................... 1327
IGNITION SIGNAL ................................................. 1328
Component Description ....................................... 1328
Wiring Diagram .................................................... 1329 Diagnostic Procedure ...........................................
1334
Component Inspection ......................................... 1339
Removal and Installation ...................................... 1340
REFRIGERANT PRESSURE SENSOR ................. 1341
Component Description ....................................... 1341
Wiring Diagram .................................................... 1342
Diagnostic Procedure ........................................... 1343
Removal and Installation ...................................... 1345
SNOW MODE SWITCH .......................................... 1346
Description ........................................................... 1346
CONSULT-II Reference Value in the Data Monitor
Mode .................................................................... 1346
Wiring Diagram .................................................... 1347
Diagnostic Procedure ........................................... 1348
Component Inspection ......................................... 1350
VARIABLE INDUCTION AIR CONTROL SYSTEM
(VIAS) ..................................................................... 1351
Description ........................................................... 1351
CONSULT-II Reference Value in Data Monitor Mode 1352
Wiring Diagram .................................................... 1353
Diagnostic Procedure ........................................... 1355
Component Inspection ......................................... 1358
Removal and Installation ...................................... 1359
MIL AND DATA LINK CONNECTOR ..................... 1360
Wiring Diagram .................................................... 1360
SERVICE DATA AND SPECIFICATIONS (SDS) ... 1362
Fuel Pressure ....................................................... 1362
Idle Speed and Ignition Timing ............................. 1362
Calculated Load Value ......................................... 1362
Mass Air Flow Sensor .......................................... 1362
Intake Air Temperature Sensor ............................ 1362
Engine Coolant Temperature Sensor ................... 1362
Fuel Tank Temperature Sensor ............................ 1362
Crankshaft Position Sensor (POS) ...................... 1362
Camshaft Position Sensor (PHASE) .................... 1362
A/F Sensor 1 Heater ............................................ 1362
Heated Oxygen sensor 2 Heater ......................... 1363
Throttle Control Motor .......................................... 1363
Fuel Injector ......................................................... 1363
Fuel Pump ............................................................ 1363

PRECAUTIONS EC-23
[VQ35DE]
C
D E
F
G H
I
J
K L
M A
EC
Revision: 2006 December 2006 FX35/FX45
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
NBS003KW
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity 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 and SB section of this Service Man-
ual.
WARNING:

To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
On Board Diagnostic (OBD) System of Engine and A/TNBS003KX
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:

Be sure to turn the ignition switch OFF and disconnect the negative battery cable before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves,
etc. will cause the MIL to light up.

Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MIL to light up 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-
locking type harness connector. For description and how to disconnect, refer to PG-72, "
HAR-
NESS CONNECTOR" .

Be sure to route and secure the harnesses properly after work. The interference of the harness
with a bracket, etc. may cause the MIL to light up due to the short circuit.

Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to the malfunction of the EVAP system or fuel injection system,
etc.

Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
PrecautionNBS003KY

Always use a 12 volt battery as power source.

Do not 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
battery 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 ignition switch OFF and then
disconnect negative battery cable.
SEF289H

EC-24
[VQ35DE]
PRECAUTIONS
Revision: 2006 December 2006 FX35/FX45

Do not 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.
Engine operation can vary slightly when the terminal is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not 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

When connecting ECM harness connector, fasten it
securely with a lever as far as it will go as shown in the fig-
ure.

When connecting or disconnecting pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM
pin terminal, when connecting pin connectors.

Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge)
voltage to develop in coil and condenser, thus resulting in
damage to ICs.

Keep engine control system harness at least 10 cm (4 in)
away from adjacent harness, to prevent engine control sys-
tem malfunctions due to receiving external noise, degraded
operation of ICs, etc.

Keep engine control system parts and harness dry.
PBIB1164E
PBIB1512E
PBIB0090E

EC-26
[VQ35DE]
PRECAUTIONS
Revision: 2006 December 2006 FX35/FX45

B1 indicates the bank 1, B2 indicates the bank 2 as shown
in the figure.

Do not operate fuel pump when there is no fuel in lines.

Tighten fuel hose clamps to the specified torque.

Do not depress accelerator pedal when starting.

Immediately after starting, do not rev up engine unneces-
sarily.

Do not rev up engine just prior to shutdown.

When installing C.B. ham radio or a mobile phone, be sure
to observe the following as it may adversely affect elec-
tronic control systems depending on installation location.
–Keep the antenna as far as possible from the electronic
control units.
–Keep the antenna feeder line more than 20 cm (8 in) away
from the harness of electronic controls.
Do not let them run parallel for a long distance.
–Adjust the antenna and feeder line so that the standing-
wave radio can be kept smaller.
–Be sure to ground the radio to vehicle body.
SEC893C
PBIB1569E
SEF709Y
SEF708Y

EC-30
[VQ35DE]
ENGINE CONTROL SYSTEM
Revision: 2006 December 2006 FX35/FX45
ENGINE CONTROL SYSTEMPFP:23710
System DiagramNBS003L1
PBIB2281E

ENGINE CONTROL SYSTEM EC-31
[VQ35DE]
C
D E
F
G H
I
J
K L
M A
EC
Revision: 2006 December 2006 FX35/FX45
Multiport Fuel Injection (MFI) SystemNBS003L2
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system under normal conditions.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.


During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D

High-load, high-speed operation


During deceleration

During high engine speed operation
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*
3
Piston position
Fuel injection
& mixture ratio
control Fuel injector
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
Air conditioner switch Air conditioner operation*
2
Wheel sensorVehicle speed*2

EC-32
[VQ35DE]
ENGINE CONTROL SYSTEM
Revision: 2006 December 2006 FX35/FX45
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst 1 can then better reduce CO, HC and NOx emissions. This system uses air fuel ratio
(A/F) sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The ECM
adjusts the injection pulse width according to the sensor voltage signal. For more information about air fuel
ratio (A/F) sensor 1, refer to EC-240, "
DTC P0131, P0151 A/F SENSOR 1" . This maintains the mixture ratio
within the range of stoichiometric (ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst 1. Even if the switching characteris-
tics of air fuel ratio (A/F) sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal from
heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.

Deceleration and acceleration

High-load, high-speed operation

Malfunction of air fuel ratio (A/F) sensor 1 or its circuit

Insufficient activation of air fuel ratio (A/F) sensor 1 at low engine coolant temperature

High engine coolant temperature

During warm-up

After shifting from N to D

When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from air fuel ratio (A/F)
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during operation (i.e., fuel injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from air fuel ratio (A/F) sensor 1 indicates whether the mixture ratio is RICH or LEAN com-
pared to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and
an increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
PBIB3020E