Nissan Primera P11. Instruction — part 77
Vacuum Hose Drawing
p
1
EGRC-solenoid valves A and B to EGR valve
p
2
EGRC-solenoid valves A and B to air duct
p
3
EGRC-solenoid valve A to vacuum pump
Refer to “System Diagram” on previous page for vacuum control system.
YEC131A
ENGINE AND EMISSION CONTROL OVERALL SYSTEM
CD20T
EC-13
System Chart
Crankshaft position sensor
(TDC)
E
ECM
Control sleeve position sensor
E
Fuel temperature sensor
E
Mass air flow sensor
E
Engine coolant temperature
sensor
E
Needle lift sensor
E
Accelerator position sensor
E
Accelerator position switch
E
Air conditioner switch
E
Ignition switch (ON & ST POS.)
E
Battery voltage
E
Vehicle speed sensor or ABS
actuator and electric unit (con-
trol unit)
E
Brake switch
E
Atmospheric pressure sensor
E
E
Fuel injection control
E
Electric governor
E
Fuel injection timing control
E
Injection timing control
valve
E
Fuel cut control
E
Fuel cut solenoid valve
E
Glow control system
E
Glow relay & glow lamp
E
On board diagnostic system
E
Malfunction indicator
(On the instrument panel)
E
EGR valve control
E
EGRC-solenoid valve A & B
E
Cooling fan control
E
Cooling fan relays
E
Air conditioning cut control
E
Air conditioner relay
E
Cooling fan motor control
E
Cooling fan relay
ENGINE AND EMISSION CONTROL OVERALL SYSTEM
CD20T
EC-14
Glow Control System
SYSTEM DESCRIPTION
Crankshaft position sensor (TDC)
E
Engine speed
ECM
E
Glow relay
E
Glow plugs
Engine coolant temperature sensor
E
Engine coolant temperature
E
Glow lamp
When coolant temperature is lower than 75°C (167°F):
●
Ignition 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.
●
Starting
After starting the engine, current will flow through the glow
plugs for 300 seconds, or until the coolant temperature
exceeds 50°C (122°F).
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 sensor
E
Engine coolant temperature
ECM
E
Electric
governor
Crankshaft position sensor (TDC)
E
Engine speed
Control sleeve position sensor
E
Control 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 DESCRIPTION
CD20T
EC-15
IDLE CONTROL
Input/output signal line
Engine coolant temperature sensor
E
Engine coolant temperature
ECM
E
Electric
governor
Crankshaft position sensor (TDC)
E
Engine speed
Air conditioner switch
E
Air conditioner operation
Control sleeve position sensor
E
Control sleeve position
Accelerator position switch
E
Idle position
Vehicle speed sensor or ABS actuator
and electric unit (control unit)
E
Vehicle 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)
E
Engine speed
ECM
E
Electric
governor
Control sleeve position sensor
E
Control sleeve position
Accelerator position sensor
E
Accelerator position
Vehicle speed sensor or ABS actuator
and electric unit (control unit)
E
Vehicle 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 DESCRIPTION
CD20T
Fuel Injection System (Cont’d)
EC-16
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