Crankshaft sensor NISSAN TEANA 2014 Service Manual

EC-1
ENGINE
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SECTION EC
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EC
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CONTENTS
ENGINE CONTROL SYSTEM
QR25DE
PRECAUTION ................ ..............................
15
PRECAUTIONS .............................................. ....15
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ....
15
Precaution for Procedure without Cowl Top Cover ....15
On Board Diagnostic (OBD) System of Engine
and CVT .............................................................. ....
15
General Precautions ...............................................16
PREPARATION ...........................................19
PREPARATION .............................................. ....19
Special Service Tools .......................................... ....19
Commercial Service Tools ......................................19
SYSTEM DESCRIPTION .............................21
COMPONENT PARTS ................................... ....21
Component Parts Location ................................ ....21
ECM ........................................................................25
Accelerator Pedal Position Sensor ...................... ....25
Electric Throttle Control Actuator ........................ ....25
Ignition Coil With Power Transistor .........................26
Fuel Injector ........................................................ ....26
Fuel Level Sensor Unit and Fuel Pump .............. ....26
Fuel Tank Temperature Sensor .......................... ....27
Mass Air Flow Sensor (With Intake Air Tempera-
ture Sensor) ........................................................ ....
27
Manifold Absolute Pressure Sensor ........................28
Engine Coolant Temperature Sensor .................. ....28
Crankshaft Position Sensor (POS) ..........................29
Camshaft Position Sens or (PHASE) .......................29
Intake Valve Timing Cont rol Solenoid Valve ...........30
Intake Valve Timing Intermediate Lock Control
Solenoid Valve .................................................... ....
30
Exhaust Valve Timing Control Position Sensor .......30
Exhaust Valve Timing Control Solenoid Valve ........31
Intake Manifold Runner Control Valve ................. ....31
Intake Manifold Tuning Valve ..................................31
Air Fuel Ratio (A/F) Sensor 1 ..................................32
Heated Oxygen Sensor 2 ........................................32
Knock Sensor ..........................................................33
Engine Oil Pressure Sensor ....................................33
Engine Oil Temperature Sensor .......................... ....33
Cooling Fan .............................................................34
EVAP Canister .........................................................34
EVAP Canister Purge Volu me Control Solenoid
Valve .................................................................... ....
34
EVAP Canister Vent Control Valve ..........................35
EVAP Control System Pres sure Sensor ..................35
Battery Current Sensor (With Battery Tempera-
ture Sensor) ......................................................... ....
35
Malfunction Indicator lamp (MIL) .............................36
Oil Pressure Warning Lamp ....................................36
Refrigerant Pressure Sensor ............................... ....36
Stop Lamp Switch & Brake Pedal Position Switch ....36
ASCD Steering Switch .............................................37
Information Display ..................................................37
STRUCTURE AND OPERATION .....................38
Positive Crankcase Ventilation ................................38
On Board Refueling Vapor Recovery (ORVR) ........39
SYSTEM ............................................................40
ENGINE CONTROL SYSTEM ........................ ...........40
ENGINE CONTROL SYSTEM : System Descrip-
tion ....................................................................... ....
40
ENGINE CONTROL SYSTEM : Fail Safe ..............41
MULTIPORT FUEL INJECTION SYSTEM ................43
MULTIPORT FUEL INJECTION SYSTEM : Sys-
tem Description (with auto matic air conditioner) ......
43
MULTIPORT FUEL INJECTION SYSTEM : Sys-
tem Description (with manual air conditioner) .........
46
ELECTRIC IGNITION SYSTEM .................................48
ELECTRIC IGNITION SYSTEM : System De-
scription ............................................................... ....
48
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EC-4
DTC Logic ..............................................................255
Diagnosis Procedure .............................................256
Component Inspection ...........................................256
P0130 A/F SENSOR 1 .....................................258
DTC Logic ............................................................ ..258
Component Function Check ..................................259
Diagnosis Procedure .............................................259
P0131 A/F SENSOR 1 .....................................262
DTC Logic ............................................................ ..262
Diagnosis Procedure .............................................263
P0132 A/F SENSOR 1 .....................................265
DTC Logic ............................................................ ..265
Diagnosis Procedure .............................................266
P0137 HO2S2 ..................................................268
DTC Logic ............................................................ ..268
Component Function Check ..................................269
Diagnosis Procedure .............................................270
Component Inspection ...........................................271
P0138 HO2S2 ..................................................274
DTC Logic ............................................................ ..274
Component Function Check ..................................275
Diagnosis Procedure .............................................276
Component Inspection ...........................................279
P0139 HO2S2 ..................................................282
DTC Logic ............................................................ ..282
Component Function Check ..................................283
Diagnosis Procedure .............................................284
Component Inspection ...........................................286
P014C, P014D, P015A, P015B, A/F SENSOR
1 ...................................................................... .
289
DTC Logic ............................................................ ..289
Diagnosis Procedure .............................................291
P0171 FUEL INJECTION SYSTEM FUNC-
TION ................................................................ .
294
DTC Logic ............................................................ ..294
Diagnosis Procedure .............................................295
P0172 FUEL INJECTION SYSTEM FUNC-
TION ................................................................ .
298
DTC Logic ............................................................ ..298
Diagnosis Procedure .............................................299
P0181 FTT SENSOR .......................................302
DTC Logic ............................................................ ..302
Component Function Check ..................................303
Diagnosis Procedure .............................................304
Component Inspection ...........................................305
P0182, P0183 FTT SENSOR ...........................306
DTC Logic ............................................................ ..306
Diagnosis Procedure .............................................306
Component Inspection ...........................................307
P0196 EOT SENSOR .......................................309
DTC Logic ............................................................ .309
Component Function Check .................................311
Diagnosis Procedure .............................................311
Component Inspection ..........................................311
P0197, P0198 EOT SENSOR ...........................312
DTC Logic ............................................................ .312
Diagnosis Procedure .............................................312
Component Inspection ..........................................313
P0222, P0223 TP SENSOR ..............................315
DTC Logic ............................................................ .315
Diagnosis Procedure .............................................315
Component Inspection ..........................................317
P0300, P0301, P0302, P0303, P0304 MIS-
FIRE ................................................................ ..
318
DTC Logic ............................................................ .318
Diagnosis Procedure .............................................319
P0327, P0328 KS .............................................324
DTC Logic ............................................................ .324
Diagnosis Procedure .............................................324
Component Inspection ..........................................325
P0335 CKP SENSOR (POS) ............................326
DTC Logic ............................................................ .326
Diagnosis Procedure .............................................326
Component Inspection (Crankshaft Position sen-
sor) ....................................................................... .
328
P0340 CMP SENSOR (PHASE) .......................329
DTC Logic ............................................................ .329
Diagnosis Procedure .............................................329
Component Inspection (Camshaft position sen-
sor) ....................................................................... .
331
P0420 THREE WAY CATALYST FUNCTION ..332
DTC Logic ............................................................ .332
Component Function Check .................................333
Diagnosis Procedure .............................................334
P0441 EVAP CONTROL SYSTEM ..................337
DTC Logic ............................................................ .337
Component Function Check .................................338
Diagnosis Procedure .............................................339
P0443 EVAP CANISTER PURGE VOLUME
CONTROL SOLENOID VALVE ...................... ..
342
DTC Logic ............................................................ .342
Diagnosis Procedure .............................................343
Component Inspection ..........................................345
P0444, P0445 EVAP CANISTER PURGE
VOLUME CONTROL SO LENOID VALVE .......
347
DTC Logic ............................................................ .347
Diagnosis Procedure .............................................347
Component Inspection ..........................................349
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EC-5
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EC A
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P0447 EVAP CANISTER VENT CONTROL
VALVE ............................................................ ..
350
DTC Logic ........................................................... ..350
Diagnosis Procedure .............................................350
Component Inspection ..........................................352
P0448 EVAP CANISTER VENT CONTROL
VALVE ............................................................ ..
354
DTC Logic ........................................................... ..354
Diagnosis Procedure .............................................355
Component Inspection ..........................................356
P0451 EVAP CONTROL SYSTEM PRES-
SURE SENSOR .............................................. ..
358
DTC Logic ........................................................... ..358
Diagnosis Procedure .............................................359
Component Inspection ..........................................361
P0452 EVAP CONTROL SYSTEM PRES-
SURE SENSOR .............................................. ..
362
DTC Logic ........................................................... ..362
Diagnosis Procedure .............................................363
Component Inspection ..........................................364
P0453 EVAP CONTROL SYSTEM PRES-
SURE SENSOR .............................................. ..
366
DTC Logic ........................................................... ..366
Diagnosis Procedure .............................................367
Component Inspection ..........................................369
P0456 EVAP CONTROL SYSTEM ..................370
DTC Logic ........................................................... ..370
Diagnosis Procedure .............................................371
Component Inspection ..........................................375
P0460 FUEL LEVEL SENSOR ........................376
DTC Logic ........................................................... ..376
Diagnosis Procedure .............................................376
P0461 FUEL LEVEL SENSOR ........................377
DTC Logic ........................................................... ..377
Component Function Check ..................................377
Diagnosis Procedure .............................................378
P0462, P0463 FUEL LEVEL SENSOR ............379
DTC Logic ........................................................... ..379
Diagnosis Procedure .............................................379
P0500 VSS .......................................................380
Description .......................................................... ..380
DTC Logic .............................................................380
Diagnosis Procedure .............................................380
P0506 ISC SYSTEM .........................................382
Description .......................................................... ..382
DTC Logic .............................................................382
Diagnosis Procedure .............................................382
P0507 ISC SYSTEM .........................................384
Description .......................................................... ..384
DTC Logic .............................................................384
Diagnosis Procedure ........................................... ..384
P050A, P050B, P050E COLD START CON-
TROL ...............................................................
386
Description ........................................................... ..386
DTC Logic ..............................................................386
Diagnosis Procedure .............................................387
P0520 EOP SENSOR ......................................388
DTC Logic ..............................................................388
Diagnosis Procedure .............................................388
Component Inspection ...........................................390
P0524 ENGINE OIL PRESSURE ....................391
DTC Logic ..............................................................391
Diagnosis Procedure .............................................392
Component Inspection ...........................................393
P052A, P052B INTAKE VALVE TIMING CON-
TROL ...............................................................
394
DTC Logic ............................................................ ..394
Diagnosis Procedure .............................................394
Component Inspection (Intake Valve Timing Con-
trol Solenoid Valve) ............................................. ..
396
Component Inspection (Intake Valve Timing Inter-
mediate Lock Control Solenoid Valve) ................ ..
397
Component Inspection (Crankshaft Position sen-
sor) ...................................................................... ..
397
Component Inspection (Camshaft position sen-
sor) ...................................................................... ..
398
P0603 ECM .....................................................400
DTC Logic ..............................................................400
Diagnosis Procedure .............................................400
P0604 ECM .....................................................401
DTC Logic ..............................................................401
Diagnosis Procedure .............................................401
P0605 ECM .....................................................402
DTC Logic ..............................................................402
Diagnosis Procedure .............................................402
P0606 ECM .....................................................403
DTC Logic ..............................................................403
Diagnosis Procedure .............................................403
P0607 ECM .....................................................404
DTC Logic ..............................................................404
Diagnosis Procedure .............................................404
P060A ECM .....................................................405
DTC Logic ..............................................................405
Diagnosis Procedure .............................................405
P060B ECM .....................................................406
DTC Logic ..............................................................406
Diagnosis Procedure .............................................406
P0643 SENSOR POWER SUPPLY ................407
Description .............................................................407
DTC Logic ..............................................................407
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EC-8
POSITIVE CRANKCASE VENTILATION ........539
Inspection ............................................................ ..539
REMOVAL AND INSTALLATION ..............540
ECM ................................................................ .540
Removal and Installation ..................................... ..540
SERVICE DATA AND SPECIFICATIONS
(SDS) .............. ............................................
541
SERVICE DATA AND SPECIFICATIONS
(SDS) ............................................................... .
541
Idle Speed ........................................................... ..541
Ignition Timing .......................................................541
Calculated Load Value ..........................................541
Mass Air Flow Sensor ............................................541
VQ35DE
PRECAUTION .............. ..............................
542
PRECAUTIONS .............................................. .542
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. ..
542
On Board Diagnostic (OBD) System of Engine
and CVT .............................................................. ..
542
General Precautions ..............................................543
PREPARATION ..........................................546
PREPARATION .............................................. .546
Special Service Tools .......................................... ..546
Commercial Service Tools .....................................546
SYSTEM DESCRIPTION ...........................548
COMPONENT PARTS .................................... .548
ENGINE CONTROL SYSTEM .................................548
ENGINE CONTROL SYSTEM : Component Parts
Location ............................................................... ..
548
Accelerator Pedal Position Sensor ........................552
Air Fuel Ratio (A/F) Sensor 1 ................................552
ASCD Steering Switch ...........................................553
Battery Current Sensor (With Battery Tempera-
ture Sensor) ......................................................... ..
553
Camshaft Position Sensor (PHASE) .....................554
Cooling Fan ......................................................... ..554
Crankshaft Position Sensor (POS) ........................554
ECM .......................................................................555
Electric Throttle Control Actuator ......................... ..555
Electronic Controlled Engine Mount .................... ..556
Engine Coolant Temperature Sensor ....................556
Engine Oil Pressure Sensor ................................ ..557
Engine Oil Temperature Sensor ............................557
EVAP Canister ..................................... ..................557
EVAP Canister Purge Volu me Control Solenoid
Valve .................................................................... ..
557
EVAP Canister Vent Control Valve ........................558
EVAP Control System Pressu re Sensor ................558
Fuel Injector ......................................................... .558
Fuel Level Sensor Unit and Fuel Pump (With Fuel
Tank Temperature Sensor) .................................. .
558
Heated Oxygen Sensor 2 ......................................559
Ignition Coil (With Power Transistor) ....................560
Intake Valve Timing Control Solenoid Valve .........560
Knock Sensor ....................................................... .560
Malfunction Indicator lamp (MIL) ...........................560
Mass Air Flow Sensor (With Intake Air Tempera-
ture Sensor) ......................................................... .
560
Oil Pressure Warning Lamp ..................................561
Power Valve Actuator 1 and 2 ..............................561
Refrigerant Pressure Sensor ................................562
Stop Lamp Switch & Brak e Pedal Position Switch .562
VIAS Control Solenoid Valve 1 and 2 .................. .562
STRUCTURE AND OPERATION .....................563
Positive Crankcase Ventilation (PCV) ...................563
On Board Refueling Vapor Recovery (ORVR) ..... .564
SYSTEM ...........................................................565
ENGINE CONTROL SYSTEM ................................ .565
ENGINE CONTROL SYSTEM : System Descrip-
tion ....................................................................... .
565
ENGINE CONTROL SYSTEM : Fail-safe .............566
MULTIPORT FUEL INJECTION SYSTEM ............. .568
MULTIPORT FUEL INJECTION SYSTEM : Sys-
tem Description .................................................... .
568
ELECTRIC IGNITION SYSTEM ............................. .571
ELECTRIC IGNITION SYSTEM : System De-
scription ................................................................ .
571
AIR CONDITIONING CUT CONTROL ................... .572
AIR CONDITIONING CUT CONTROL : System
Description ........................................................... .
573
AUTOMATIC SPEED CONTROL DEVICE (ASCD) .574
AUTOMATIC SPEED CONTROL DEVICE (AS-
CD) : System Description ..................................... .
574
COOLING FAN CONTROL .................................... .575
COOLING FAN CONTROL : System Description .575
ELECTRONIC CONTROLLED ENGINE MOUNT .. .577
ELECTRONIC CONTROLLED ENGINE MOUNT
: System Description ............................................ .
577
EVAPORATIVE EMISSION SYSTEM .....................579
EVAPORATIVE EMISSION SYSTEM : System
Description ........................................................... .
580
THROTTLE CONTROL ...........................................581
THROTTLE CONTROL : Syst em Description ......581
INTAKE VALVE TIMING CONTROL ..................... .582
INTAKE VALVE TIMING CONTROL : System De-
scription ................................................................ .
583
ENGINE PROTECTION CONTROL AT LOW EN-
GINE OIL PRESSURE ........................................... .
583
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EC-16
< PRECAUTION >[QR25DE]
PRECAUTIONS
• Be sure to connect rubber tubes properly afte
r 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 info rmation (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
General PrecautionsINFOID:0000000009462050
•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 bat-
tery 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 ig nition switch OFF and then dis-
connect battery ground cable.
• 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 slight ly when the terminal is dis-
connected. However, this is no t an indication of a malfunc-
tion. Do not replace parts b ecause 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 or disconnect ing 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) volt-
age to develop in coil and co ndenser, thus resulting in dam-
age to ICs.
• Keep engine control system harness at least 10 cm (4 in) away
from adjacent harness, to preven t engine control system mal-
functions due to receiving exter nal noise, degraded operation
of ICs, etc.
• Keep engine control system parts and harness dry.
• Before replacing ECM, perform ECM Terminals and Reference
Value inspection and make sure ECM functions properly.
Refer to EC-88, "Reference Value"
.
• Handle mass air flow sensor carefully to avoid damage.
• Do not clean mass air flow senso r with any type of detergent.
• Do not disassemble electric throttle control actuator.
• Even a slight leak in the ai r intake system can cause serious
incidents.
• Do not shock or jar the camshaft position sensor (PHASE),
crankshaft position sensor (POS).
SEF289H
PBIA9222J
PBIB0090E
MEF040D
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EC-22
< SYSTEM DESCRIPTION >[QR25DE]
COMPONENT PARTS
ENGINE COMPARTMENT
Intake manifold runner control valve actuator
EC-31, "Intake Manifold Runner Control Valve"
Electric throttle control actuator
(with built in throttle position sensor and throttle control motor) EC-25, "Electric Thrott
le Control Actuator"
EVAP service port When perform the EVAP leak check, positive pressure is
delivered to the EVAP system through the EVAP service
port.
Refer to EC-537, "Inspection"
.
No. Component Function
JPBIA5840ZZ
Engine rear side Intake side
: Vehicle front
No. Component Function
Exhaust valve timing control position sensor EC-30, "Exhaust Valve Timing Control Position Sensor"
Camshaft position sensor (PHASE)EC-29, "Camshaft Position Sensor (PHASE)"
PCV valveThe positive crankcase ventilation (PCV) valve is provided
to conduct crankcase blow-by gas to the intake manifold.
Fuel injector EC-26, "Fuel Injector"
Crankshaft position sensor (POS)EC-29, "Crankshaft Position Sensor (POS)"
Knock sensorEC-33, "Knock Sensor"
Engine oil temperature sensorEC-33, "Engine Oil Temperature Sensor"
Engine oil pressure sensorEC-33, "Engine Oil Pressure Sensor"
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COMPONENT PARTSEC-29
< SYSTEM DESCRIPTION > [QR25DE]
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*: These data are reference values and are measured between ECM terminals.
Crankshaft Position Sensor (POS)INFOID:0000000009462064
The crankshaft position sensor (POS
) is located on the oil pan facing
the gear teeth (cogs) of the signal pl ate. It detects the fluctuation of
the engine revolution.
The sensor consists of a permanent magnet and Hall IC.
When the engine is running, the high and low parts of the teeth
cause the gap with the sensor to change.
The changing gap causes the magnet ic field near the sensor to
change.
Due to the changing magnetic fiel d, the voltage from the sensor
changes.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
ECM receives the signals as shown in the figure.
Camshaft Position Sensor (PHASE)INFOID:0000000009462065
The camshaft position sensor (PHASE) senses the retraction of
intake camshaft to identify a particular cylinder. The camshaft posi-
tion sensor (PHASE) senses the piston position.
When the crankshaft position sensor (POS) system becomes inoper-
ative, the camshaft position sensor (PHASE) provides various con-
trols of engine parts instead, utilizing timing of cylinder identification
signals.
The sensor consists of a permanent magnet and Hall IC.
When engine is running, the high and low parts of the teeth cause
the gap with the sensor to change.
The changing gap causes the magnet ic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor changes.
Engine coolant temperature
[° C ( °F)] Vo l ta g e* (V)
Resistance (k
Ω)
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.37 - 2.63
50 (122) 2.2 0.68 - 1.00
90 (194) 1.0 0.236 - 0.260
SEF012P
JPBIA5848ZZ
JMBIA0714GB
JPBIA5846ZZ
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EC-44
< SYSTEM DESCRIPTION >[QR25DE]
SYSTEM
conditioner)
INFOID:0000000009462093
SYSTEM DIAGRAM
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). T he amount of fuel injected is a program value in the
ECM memory. The program value is preset by engi ne operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from t he crankshaft position sensor (POS), camshaft position
sensor (PHASE) and the ma ss air flow sensor.
VARIOUS FUEL INJECTION I NCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compens ated 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
JPBIA5978GB
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SYSTEMEC-47
< SYSTEM DESCRIPTION > [QR25DE]
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by input signals (for engine speed and intake air) from t
he crankshaft position sensor (POS), camshaft position
sensor (PHASE) and the mass air flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compens ated 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
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system prov ides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better r educe CO, HC and NOx emissions. This system uses A/F
sensor 1 in the exhaust manifold to monitor whether t he engine operation is rich or lean. The ECM adjusts the
injection pulse width according to the sensor voltage si gnal. For more information about A/F sensor 1, refer to
EC-32, "Air Fuel Ratio (A/F) Sensor 1"
. This maintains the mixture rati o 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 th ree way catalyst (manifold). Even if the switching
characteristics of A/F sensor 1 shift, the air-fuel rati o is controlled to stoichiometric by the signal from heated
oxygen sensor 2.
• Open Loop Control
The open loop system condition refers to when the EC M 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 A/F sensor 1 or its circuit
- Insufficient activation of 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 A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM cont rols the basic mixture ratio as close to the theoret-
ical mixture ratio as possible. However, the basic mi xture ratio is not necessarily controlled as originally
designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes dur-
ing 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 co mpared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
PBIB2793E
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SYSTEMEC-49
< SYSTEM DESCRIPTION > [QR25DE]
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The ECM receives information such as the injecti
on pulse width and camshaft position sensor (PHASE) sig-
nal. Computing this information, ignition si gnals are transmitted to the power transistor.
During the following conditions, the ignition timing is revi sed by the ECM according to the other data stored in
the ECM.
• At starting
• During warm-up
•At idle
• At low battery voltage
• 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.
INTAKE VALVE TIMING CONTROL
INTAKE VALVE TIMING CONTROL : System DescriptionINFOID:0000000009462096
INTAKE VALVE TIMING CONTROL
System Diagram
Input/Output Signal Chart
*: This signal is sent to the ECM through CAN communication line
JPBIA4760GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed and piston position
Intake valve
timing control Intake valve timing control
solenoid valve
Camshaft position sensor (PHASE)
Engine oil temperature sensor Engine oil temperature
Engine coolant temperature sensor Engine coolant temperature
Combination meter Vehicle speed*
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM