1999 NISSAN PRIMERA Control

Glow Control System
SYSTEM DESCRIPTION
Crankshaft position sensor (TDC)EEngine speed
ECMEGlow relayEGlow plugs
Engine coolant temperature sensorEEngine coolant temperatureEGlow lamp
When coolant temperature is lower than 75ÉC (167ÉF):
lIgnition switch ON
After the ignition switch has been turned to ON, the glow
relay turns ON for a period of time depending on the engine
coolant temperature, allowing current to flow through the
glow plugs.
lStarting
After starting the engine, current will flow through the glow
plugs for 300 seconds, or until the coolant temperature
exceeds 50ÉC (122ÉF).
Fuel Injection System
SYSTEM DESCRIPTION
Three types of fuel injection control are provided to accommodate the engine operating conditions; normal
control, idle control and start control. The ECM determines the appropriate fuel injection control. Under each
control, the amount of fuel injected is compensated to improve engine performance. The ECM performs duty
cycle control on the electric governor (built into the fuel injection pump) according to sensor signals to com-
pensate the amount of fuel injected to the preset value.
START CONTROL
Input/output signal line
Engine coolant temperature sensorEEngine coolant temperature
ECM
EElectric
governorCrankshaft position sensor (TDC)EEngine speed
Control sleeve position sensor
EControl sleeve position
When starting, the ECM adapts the fuel injection system for the
start control. The amount of fuel injected at engine starting is a
preset program value in the ECM. The program is determined by
the engine speed and engine coolant temperature.
For better startability under cool engine conditions, the lower the
coolant temperature becomes, the greater the amount of fuel
injected. The ECM ends the start control when the engine speed
reaches a coolant temperature dependent value.
SEF648S Coolant temperature
getting lower
Engine rpm
Fuel injection volume
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONCD20T
EC-15

IDLE CONTROL
Input/output signal line
Engine coolant temperature sensorEEngine coolant temperature
ECM
EElectric
governor
Crankshaft position sensor (TDC)EEngine speed
Air conditioner switch
EAir conditioner operation
Control sleeve position sensor
EControl sleeve position
Accelerator position switch
EIdle position
Vehicle speed sensor or ABS actuator
and electric unit (control unit)
EVehicle speed
When the ECM determines that the engine speed is at idle, the fuel injection system is adapted for the idle
control. The ECM regulates the amount of fuel injected corresponding to changes in load applied to the
engine to keep engine speed constant. During the first 270s after a cold start, the ECM also provides the
system with a fast idle control in response to the engine coolant temperature.
NORMAL CONTROL
Input/output signal line
Crankshaft position sensor (TDC)EEngine speed
ECM
EElectric
governor
Control sleeve position sensorEControl sleeve position
Accelerator position sensor
EAccelerator position
Vehicle speed sensor or ABS actuator
and electric unit (control unit)
EVehicle speed
The amount of fuel injected under normal driving conditions is
determined according to sensor signals. The crankshaft position
sensor (TDC) detects engine speed and the accelerator position
sensor detects accelerator position. These sensors send signals
to the ECM.
The fuel injection data, predetermined by correlation between
various engine speeds and accelerator positions, are stored in
the ECM memory, forming a map. The ECM determines the
optimal amount of fuel to be injected using the sensor signals in
comparison with the map.
SEF649S
Fuel injection volume
Accelerator
opening larger
Engine rpm
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONCD20T
Fuel Injection System (Cont'd)
EC-16

FUEL TEMPERATURE COMPENSATION
Input/output signal line
Fuel temperature sensorEFuel temperature
ECM
EElectric
governorCrankshaft position sensor (TDC)EEngine speed
Control sleeve position sensor
EControl sleeve position
The amount of fuel leaking at or around high-pressure parts inside the fuel injection pump varies with fuel
temperature and engine speed. This will result in a difference between the target amount of fuel injected and
the actual amount. The ECM compensates for the actual amount depending on the signal from the fuel
temperature sensor, the control sleeve position sensor and the crankshaft position sensor.
DECELERATION CONTROL
Input/output signal line
Accelerator sensorEAccelerator position
ECM
EElectric
governor
Camshaft position sensor (PUMP)EEngine speed
The ECM cuts power supply delivery to the electric governor during deceleration for better fuel efficiency.
The ECM determines the time of deceleration according to signals from the accelerator sensor and cam-
shaft position sensor (PUMP).
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONCD20T
Fuel Injection System (Cont'd)
EC-17

Fuel Injection Timing System
SYSTEM DESCRIPTION
The fuel injection timing system determines the optimal fuel injection timing, based on engine speed, injec-
tion quantity, engine coolant temperature and atmospheric pressure. The timing is formed by a basic value
(Basic Control) and two correction values. By performing a duty cycle signal on the timing control valve, the
ECM allows the valve to provide optimal injection timing. The ECM also performs feedback control on the
timing control valve using the signal from the needle lift sensor which detects the actual fuel injection tim-
ing.
BASIC CONTROL
Input/output signal line
Crankshaft position sensor (TDC)EEngine speed
ECM
E
Injection
timing con-
trol valveNeedle lift sensorEInjection timing
Control sleeve position sensor
EControl sleeve position
The optimal fuel injection timing data, predetermined in propor-
tion to engine speeds and amount of fuel injected, are stored in
the ECM memory. The ECM uses the data to control the fuel
injection timing.
HIGH ALTITUDE COMPENSATION
Crankshaft position sensorEEngine speed
ECM
E
Injection
timing
control
valveControl sleeve position sensorEControl sleeve position
Atmospheric pressure sensor
EAtmospheric pressure
Needle lift sensor
EInjection timing
Fuel temperature sensor
EFuel temperature
For better drivability in high altitude areas, the fuel injection tim-
ing is advanced and the fuel quantity is reduced according to the
atmospheric pressure.
SEF650S
Fuel injection timing
BTDC
(degree)Fuel injection
volume
Large
Small
Engine rpm
NEF771
Fuel injection
timing compensation
Normal
High altitude
Engine rpm
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONCD20T
EC-18

ENGINE COOLANT TEMPERATURE COMPENSATION (During driving)
Input/output signal line
Crankshaft position sensor (TDC)EEngine speed
ECM
E
Injection
timing con-
trol valveEngine coolant temperature sensorEEngine coolant temperature
Needle lift sensor
EInjection timing
Control sleeve position sensor
EControl sleeve position
For better exhaust efficiency under cool engine conditions, the
fuel injection timing is controlled within a compensation range
depending on the engine speed, engine coolant temperature and
amount of fuel injected.
ENGINE COOLANT TEMPERATURE COMPENSATION (When starting)
Input/output signal line
Crankshaft position sensor (TDC)EEngine speed
ECM
E
Injection
timing con-
trol valveEngine coolant temperature sensorEEngine coolant temperature
Needle lift sensor
EIgnition timing
For better startability under cool engine conditions, the fuel injec-
tion timing is compensated according to the engine coolant tem-
perature.
SEF652S
Fuel injection
timing compensation
Engine coolant
temperature
Low
High
Engine rpm
SEF651S
Fuel injection
timing compensation
Engine coolant
temperature
High
Engine rpm Low
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONCD20T
Fuel Injection Timing System (Cont'd)
EC-19

Air Conditioning Cut Control
INPUT/OUTPUT SIGNAL LINE
Air conditioner switch or ABS actuator
and electric unit (control unit)EAir conditioner ªONº signal
ECM
EAir
conditioner
relayAccelerator position sensorEAccelerator valve opening angle
Vehicle speed sensor
EVehicle speed
Engine coolant temperature sensor
EEngine coolant temperature
SYSTEM DESCRIPTION
This system improves acceleration when the air conditioner is used.
When the accelerator pedal is fully depressed, the air conditioner is turned off for a few seconds.
When engine coolant temperature becomes excessively high, the air conditioner is turned off. This contin-
ues until the coolant temperature returns to normal.
Cooling Fan Control
INPUT/OUTPUT SIGNAL LINE
Vehicle speed sensor or ABS actuator
and electric unit (control unit)EVehicle speed
ECM
ECooling fan relay(s)Engine coolant temperature sensorEEngine coolant temperature
Air conditioner switch
EAir conditioner ªONº signal
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, and air
conditioner ON signal. The control system has 3-step control [OFF/LOW/HIGH].
Operation
NEF772
Engine coolant
temperature ÉC (ÉF)
Air conditioner is OFF
.102 (216)
.96 (205)
.20
(12).80
(50)
Vehicle speed km/h (mph)
Cooling fans do not operateCooling fans operate at high speed
Engine coolant
temperature ÉC (ÉF)
Vehicle speed km/h (mph)
.20
(12).80
(50)
.102 (216)
.96 (205)Air conditioner is ON
Cooling fans operate at low speed
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONCD20T
EC-20

Description
lIn this system blow-by gas is sucked into the air inlet pipe
through the control valve after oil separation by the oil sepa-
rator in the rocker cover.
Blow-by Control Valve
lCheck control valve for clogging and abnormalities.
Ventilation Hose
1. Check hoses and hose connections for leaks.
2. Disconnect all hoses and clean with compressed air.
If any hose cannot be freed of obstructions, replace.
SEF851S
Blow-by control
valve
FRESH AIR
BLOW BY
GASBaffle plate
SEC586B Blow-by control valve
Rocker coverIntake
manifold
SEC692
CRANKCASE VENTILATION SYSTEMCD20T
EC-21

Disassembly and Assembly
CAUTION:
lDo not disassemble the parts not shown in the illustra-
tion above.
lBefore installing injection timing control valve, apply a
coat of diesel fuel to O-ring and its mating area. Insert
injection timing control valve straight into bore in fuel
pump body. After properly positioning injection timing
control valve, visually check for fuel leaks.
lAfter assembling the parts, erase Diagnostic Trouble
Code (DTC), and perform DTC CONFIRMATION PROCE-
DURE (or OVERALL FUNCTION CHECK).
ELECTRONIC FUEL INJECTION PUMPCD20T
EC-26