2005 INFINITI FX35 Coolant sensor

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Wiring Diagram ...................................................
. 615
Diagnostic Procedure .......................................... . 616
Component Inspection ........................................ . 618
DTC P2122, P2123 APP SENSOR ....................... . 619
Component Description ....................................... . 619
CONSULT-II Reference Value in Data Monitor Mode . 619
On Board Diagnosis Logic .................................. . 619
DTC Confirmation Procedure .............................. . 620
Wiring Diagram ................................................... . 621
Diagnostic Procedure .......................................... . 622
Component Inspection ........................................ . 624
Removal and Installation ..................................... . 625
DTC P2127, P2128 APP SENSOR ....................... . 626
Component Description ....................................... . 626
CONSULT-II Reference Value in Data Monitor Mode . 626
On Board Diagnosis Logic .................................. . 626
DTC Confirmation Procedure .............................. . 627
Wiring Diagram ................................................... . 628
Diagnostic Procedure .......................................... . 629
Component Inspection ........................................ . 632
Removal and Installation ..................................... . 632
DTC P2135 TP SENSOR ....................................... . 633
Component Description ....................................... . 633
CONSULT-II Reference Value in Data Monitor Mode . 633
On Board Diagnosis Logic .................................. . 633
DTC Confirmation Procedure .............................. . 634
Wiring Diagram ................................................... . 635
Diagnostic Procedure .......................................... . 636
Component Inspection ........................................ . 639
Removal and Installation ..................................... . 639
DTC P2138 APP SENSOR .................................... . 640
Component Description ....................................... . 640
CONSULT-II Reference Value in Data Monitor Mode . 640
On Board Diagnosis Logic .................................. . 640
DTC Confirmation Procedure .............................. . 641
Wiring Diagram ................................................... . 642
Diagnostic Procedure .......................................... . 643
Component Inspection ........................................ . 647
Removal and Installation ..................................... . 647
IGNITION SIGNAL ................................................. . 648
Component Description ....................................... . 648
Wiring Diagram ................................................... . 649
Diagnostic Procedure .......................................... . 654
Component Inspection ........................................ . 659
Removal and Installation ..................................... . 660
INJECTOR CIRCUIT .............................................. . 661
Component Description ....................................... . 661
CONSULT-II Reference Value in Data Monitor Mode . 661
Wiring Diagram ................................................... . 662
Diagnostic Procedure .......................................... . 663
Component Inspection ........................................ . 667
Removal and Installation ..................................... . 667
FUEL PUMP CIRCUIT ........................................... . 668
Description .......................................................... . 668 CONSULT-II Reference Value in Data Monitor Mode
.668
Wiring Diagram .................................................... .669
Diagnostic Procedure .......................................... .670
Component Inspection ......................................... .672
Removal and Installation ..................................... .673
REFRIGERANT PRESSURE SENSOR ................. .674
Component Description ....................................... .674
Wiring Diagram .................................................... .675
Diagnostic Procedure .......................................... .676
Removal and Installation ..................................... .678
ELECTRICAL LOAD SIGNAL ............................... .679
Description ........................................................... .679
CONSULT-II Reference Value in Data Monitor Mode .679
Diagnostic Procedure .......................................... .679
ICC BRAKE SWITCH ............................................ .680
Component Description ....................................... .680
CONSULT-II Reference Value in Data Monitor Mode .680
Wiring Diagram .................................................... .681
Diagnostic Procedure .......................................... .682
Component Inspection ......................................... .687
ASCD BRAKE SWITCH ........................................ .688
Component Description ....................................... .688
CONSULT-II Reference Value in Data Monitor Mode .688
Wiring Diagram .................................................... .689
Diagnostic Procedure .......................................... .690
Component Inspection ......................................... .694
ASCD INDICATOR ................................................. .695
Component Description ....................................... .695
CONSULT-II Reference Value in Data Monitor Mode .695
Wiring Diagram .................................................... .696
Diagnostic Procedure .......................................... .697
SNOW MODE SWITCH ......................................... .698
Description ........................................................... .698
CONSULT-II Reference Value in the Data Monitor
Mode .................................................................... .698
Wiring Diagram .................................................... .699
Diagnostic Procedure .......................................... .700
Component Inspection ......................................... .702
MIL AND DATA LINK CONNECTOR ..................... .703
Wiring Diagram .................................................... .703
SERVICE DATA AND SPECIFICATIONS (SDS) ... .705
Fuel Pressure ...................................................... .705
Idle Speed and Ignition Timing ............................ .705
Calculated Load Value ......................................... .705
Mass Air Flow Sensor .......................................... .705
Intake Air Temperature Sensor ............................ .705
Engine Coolant Temperature Sensor .................. .705
Air Fuel Ratio (A/F) Sensor 1 Heater ................... .705
Heated Oxygen sensor 2 Heater ......................... .705
Crankshaft Position Sensor (POS) ...................... .705
Camshaft Position Sensor (PHASE) ................... .705
Throttle Control Motor .......................................... .705
Injector ................................................................. .706
Fuel Pump ........................................................... .706

EC-14Revision: 2005 July 2005 FX
Diagnostic Procedure ..........................................
1305
Component Inspection ......................................... 1307
Removal and Installation ..................................... 1308
DTC P2127, P2128 APP SENSOR ........................ 1309
Component Description ....................................... 1309
CONSULT-II Reference Value in Data Monitor Mode 1309
On Board Diagnosis Logic ................................... 1309
DTC Confirmation Procedure .............................. 1310
Wiring Diagram .................................................... 1311
Diagnostic Procedure .......................................... 1312
Component Inspection ......................................... 1315
Removal and Installation ..................................... 1315
DTC P2135 TP SENSOR ....................................... 1316
Component Description ....................................... 1316
CONSULT-II Reference Value in Data Monitor Mode 1316
On Board Diagnosis Logic ................................... 1316
DTC Confirmation Procedure .............................. 1317
Wiring Diagram .................................................... 1318
Diagnostic Procedure .......................................... 1319
Component Inspection ......................................... 1322
Removal and Installation ..................................... 1322
DTC P2138 APP SENSOR .................................... 1323
Component Description ....................................... 1323
CONSULT-II Reference Value in Data Monitor Mode 1323
On Board Diagnosis Logic ................................... 1323
DTC Confirmation Procedure .............................. 1324
Wiring Diagram .................................................... 1325
Diagnostic Procedure .......................................... 1326
Component Inspection ......................................... 1330
Removal and Installation ..................................... 1330
VARIABLE INDUCTION AIR CONTROL SYSTEM
(VIAS) ..................................................................... 1331
Description ........................................................... 1331
CONSULT-II Reference Value in Data Monitor Mode 1332
Wiring Diagram .................................................... 1333
Diagnostic Procedure .......................................... 1334
Component Inspection ......................................... 1337
Removal and Installation ..................................... 1338
IGNITION SIGNAL ................................................. 1339
Component Description ....................................... 1339
Wiring Diagram .................................................... 1340
Diagnostic Procedure .......................................... 1345
Component Inspection ......................................... 1349
Removal and Installation ..................................... 1350
INJECTOR CIRCUIT .............................................. 1351
Component Description ....................................... 1351
CONSULT-II Reference Value in Data Monitor Mode 1351
Wiring Diagram .................................................... 1352
Diagnostic Procedure .......................................... 1353
Component Inspection ......................................... 1357
Removal and Installation ..................................... 1357
FUEL PUMP CIRCUIT ........................................... 1358
Description ........................................................... 1358
CONSULT-II Reference Value in Data Monitor Mode 1358
Wiring Diagram .................................................... 1359
Diagnostic Procedure ........................................... 1360
Component Inspection ......................................... 1363
Removal and Installation ...................................... 1363
REFRIGERANT PRESSURE SENSOR ................. 1364
Component Description ....................................... 1364
Wiring Diagram .................................................... 1365
Diagnostic Procedure ........................................... 1366
Removal and Installation ...................................... 1368
ELECTRICAL LOAD SIGNAL ............................... 1369
Description ........................................................... 1369
CONSULT-II Reference Value in Data Monitor Mode 1369
Diagnostic Procedure ........................................... 1369
ICC BRAKE SWITCH ............................................. 1370
Component Description ....................................... 1370
CONSULT-II Reference Value in Data Monitor Mode 1370
Wiring Diagram .................................................... 1371
Diagnostic Procedure ........................................... 1372
Component Inspection ......................................... 1377
ASCD BRAKE SWITCH ......................................... 1378
Component Description ....................................... 1378
CONSULT-II Reference Value in Data Monitor Mode 1378
Wiring Diagram .................................................... 1379
Diagnostic Procedure ........................................... 1380
Component Inspection ......................................... 1384
ASCD INDICATOR ................................................. 1385
Component Description ....................................... 1385
CONSULT-II Reference Value in Data Monitor Mode
1385
Wiring Diagram .................................................... 1386
Diagnostic Procedure ........................................... 1387
SNOW MODE SWITCH .......................................... 1388
Description ........................................................... 1388
CONSULT-II Reference Value in the Data Monitor
Mode .................................................................... 1388
Wiring Diagram .................................................... 1389
Diagnostic Procedure ........................................... 1390
Component Inspection ......................................... 1392
MIL AND DATA LINK CONNECTOR ..................... 1393
Wiring Diagram .................................................... 1393
SERVICE DATA AND SPECIFICATIONS (SDS) ... 1395
Fuel Pressure ....................................................... 1395
Idle Speed and Ignition Timing ............................. 1395
Calculated Load Value ......................................... 1395
Mass Air Flow Sensor .......................................... 1395
Intake Air Temperature Sensor ............................ 1395
Engine Coolant Temperature Sensor ................... 1395
Fuel Tank Temperature Sensor ............................ 1395
Crankshaft Position Sensor (POS) ...................... 1395
Camshaft Position Sensor (PHASE) .................... 1395
Heated Oxygen Sensor 1 Heater ......................... 1395
Heated Oxygen sensor 2 Heater ......................... 1396
Throttle Control Motor .......................................... 1396
Injector ................................................................. 1396
Fuel Pump ............................................................ 1396

PREPARATION EC-29
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Commercial Service ToolsABS006K3
Tool name
(Kent-Moore No.) Description
Leak detector
i.e.: (J-41416) Locating 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 temperature sensor
Oxygen sensor thread
cleaner
i.e.: (J-43897-18)
(J-43897-12) Reconditioning the exhaust system threads
before installing a new oxygen sensor. Use with
anti-seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for
Zirconia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for
Titania Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL
specification MIL-A-
907) Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
S-NT703
S-NT704
S-NT815
S-NT705
AEM488
S-NT779

ENGINE CONTROL SYSTEM EC-31
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Revision: 2005 July 2005 FX
Multiport Fuel Injection (MFI) SystemABS006K7
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*
2Air conditioner operation
Wheel sensor*
2Vehicle speed

EC-32
[VQ35DE]
ENGINE CONTROL SYSTEM
Revision: 2005 July 2005 FX
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-488
. 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., 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.
SEF503YB

ENGINE CONTROL SYSTEM EC-33
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FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all six cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The six injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration, operation of the engine at excessively high speeds or oper-
ation of the vehicle at excessively high speeds.
Electronic Ignition (EI) SystemABS006K8
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
Firing order: 1 - 2 - 3 - 4 - 5 - 6
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor (PHASE) sig-
nal. Computing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is revised by the ECM according to the other data stored in
the ECM.

At starting

During warm-up

At idle

At low battery voltage
SEF179U
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*
2
Piston position
Ignition timing
control Power transistor
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery Battery voltage*
2
Wheel sensor*1Vehicle speed

EC-34
[VQ35DE]
ENGINE CONTROL SYSTEM
Revision: 2005 July 2005 FX

During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Fuel Cut Control (at No Load and High Engine Speed)ABS006KA
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed is over 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under EC-31, "
Multiport Fuel Injection (MFI) System" .
Sensor Input Signal to ECM ECM function Actuator
Park/neutral position (PNP) switch Neutral position
Fuel cut con-
trol Fuel injector
Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed
Wheel sensor* Vehicle speed

AIR CONDITIONING CUT CONTROL EC-35
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Revision: 2005 July 2005 FX
AIR CONDITIONING CUT CONTROLPFP:23710
Input/Output Signal ChartABS00E8X
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
System DescriptionABS00E8Y
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.

When the accelerator pedal is fully depressed.

When cranking the engine.

At high engine speeds.

When the engine coolant temperature becomes excessively high.

When operating power steering during low engine speed or low vehicle speed.

When engine speed is excessively low.

When refrigerant pressure is excessively low or high.
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch*
1Air conditioner ON signal
Air conditioner
cut control Air conditioner relay
Accelerator pedal position sensor Accelerator pedal position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
2
Engine coolant temperature sensor Engine coolant temperature
Battery Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor*
1Vehicle speed