engine NISSAN PICK-UP 2001 User Guide

Special Service ToolsNEEC0007The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool nameDescription
KV10117100
(J36471-A)
Heated oxygen sensor
wrench
NT379
Loosening or tightening heated oxygen sensor 1
with 22 mm (0.87 in) hexagon nut
KV10114400
(J-38365)
Heated oxygen sensor
wrench
NT636
Loosening or tightening heated oxygen sensor 2
a: 22 mm (0.87 in)
(J-45178)
TPS test connector
LEC120A
Used to test the throttle position sensor
Commercial Service ToolsNEEC0008
Tool name Description
Fuel filler cap adapter
NT653
Checking fuel tank vacuum relief valve opening
pressure
Socket wrench
NT705
Removing and installing engine coolant tempera-
ture sensor
PREPARATIONKA24DE (EURO OBD)
Special Service Tools
EC-3016

Engine Control Component Parts LocationNEEC0009
SEC196D
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM
KA24DE (EURO OBD)
Engine Control Component Parts Location
EC-3018

SEC302D
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM
KA24DE (EURO OBD)
Engine Control Component Parts Location
EC-3019

Circuit DiagramNEEC0010
GEC232A
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM
KA24DE (EURO OBD)
Circuit Diagram
EC-3020

System DiagramNEEC0011
SEC270D
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM
KA24DE (EURO OBD)
System Diagram
EC-3021

Vacuum Hose DrawingNEEC0012Refer to ªSystem Diagramº on EC-3021 for vacuum control system.
SEC195D
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM
KA24DE (EURO OBD)
Vacuum Hose Drawing
EC-3022

System ChartNEEC0013
Input (Sensor) ECM Function Output (Actuator)
+Camshaft position sensor
+Mass air flow sensor
+Engine coolant temperature sensor
+Heated oxygen sensor 1
+Ignition switch
+Throttle position sensor
+PNP switch
+Air conditioner switch
+Knock sensor
+Crankshaft position sensor (OBD)
+Battery voltage
+Power steering oil pressure switch
+Vehicle speed sensor
+Intake air temperature sensor
+Heated oxygen sensor 2*1
+Closed throttle position switch*2Fuel injection & mixture ratio control Injectors
Distributor ignition system Power transistor
Idle air control systemIACV-AAC valve and IACV-FICD
solenoid valve
Fuel pump control Fuel pump relay
Heated oxygen sensor 1 monitor & on
board diagnostic systemMalfunction indicator
(On the instrument panel)
Heated oxygen sensors 1, 2 heater control Heated oxygen sensor heater
EVAP canister purge flow controlEVAP canister purge volume con-
trol solenoid valve
Air conditioning cut control Air conditioner relay
*1: Under normal conditions, this sensor is not for engine control operation.
*2: This switch will operate in place of the throttle position sensor to control EVAP parts if the sensor malfunctions.
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM
KA24DE (EURO OBD)
System Chart
EC-3023

Multiport Fuel Injection (MFI) System
DESCRIPTIONNEEC0014Input/Output Signal ChartNEEC0014S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor Engine speed and piston position
Fuel injec-
tion & mix-
ture ratio
controlInjector Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 Density of oxygen in exhaust gas
Throttle position sensorThrottle position
Throttle valve idle position
PNP switch Gear position
Vehicle speed sensor Vehicle speed
Ignition switch Start signal
Air conditioner switch Air conditioner operation
Knock sensor Engine knocking condition
Battery Battery voltage
Power steering oil pressure switch Power steering operation
Heated oxygen sensor 2* Density of oxygen in exhaust gas
* Under normal conditions, this sensor is not for engine control operation.
Basic Multiport Fuel Injection SystemNEEC0014S02The 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 camshaft position sensor and the mass air
flow sensor.
Various Fuel Injection Increase/Decrease CompensationNEEC0014S03In addition, the amount of fuel injected is compensated to improve engine performance under various oper-
ating conditions as listed below.

+During warm-up
+When starting the engine
+During acceleration
+Hot-engine operation
+High-load, high-speed operation

+During deceleration
+During high engine speed operation
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTION
KA24DE (EURO OBD)
Multiport Fuel Injection (MFI) System
EC-3024

Mixture Ratio Feedback Control (Closed loop control)NEEC0014S04
SEC303D
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission con-
trol. The three way catalyst can then better reduce CO, HC and NOx emissions. This system uses a heated
oxygen sensor 1 in the exhaust manifold to monitor if the engine operation is rich or lean. The ECM adjusts
the injection pulse width according to the sensor voltage signal. For more information about the heated oxy-
gen sensor 1, refer to EC-3213. 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. Even if the switching characteris-
tics of the heated oxygen sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal from the
heated oxygen sensor 2.
Open Loop ControlNEEC0014S05The 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 heated oxygen sensor 1 or its circuit
+Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature
+High engine coolant temperature
+During warm-up
+When starting the engine
Mixture Ratio Self-learning ControlNEEC0014S06The mixture ratio feedback control system monitors the mixture ratio signal transmitted from the heated oxy-
gen 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
originally designed. Both manufacturing differences (i.e., mass air flow sensor hot film) 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 ªinjection pulse durationº to automatically compensate for the difference between
the two ratios.
ªFuel trimº refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
ªShort term fuel trimº is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from the heated oxygen 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.
ªLong term fuel trimº 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.
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTION
KA24DE (EURO OBD)
Multiport Fuel Injection (MFI) System
EC-3025

Fuel Injection TimingNEEC0014S07
SEF337W
Two types of systems are used.
Sequential Multiport Fuel Injection System
NEEC0014S0701Fuel 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
NEEC0014S0702Fuel is injected simultaneously into all four cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The four 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-offNEEC0014S08Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
Distributor Ignition (DI) System
DESCRIPTIONNEEC0015Input/Output Signal ChartNEEC0015S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor Engine speed and piston position
Ignition tim-
ing controlPower transistor Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensorThrottle position
Throttle valve idle position
Vehicle speed sensor Vehicle speed
Ignition switch Start signal
Knock sensor Engine knocking
PNP switch Gear position
Battery Battery voltage
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTION
KA24DE (EURO OBD)
Multiport Fuel Injection (MFI) System
EC-3026