2001 NISSAN PICK-UP coolant

Fuel Injection Control System
DESCRIPTION
System description
Three types of fuel injection control are provided to accommodate 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.
Pulse signals are exchanged between ECM and electronic control fuel injection pump (control unit is built-
in). The fuel injection pump control unit performs duty control on the spill valve (built into the fuel injection
pump) according to the input signals to compensate the amount of fuel injected to the preset value.
Start control
Input/output signal chart
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection con-
trol (start control)Electronic control fuel injec-
tion pump Crankshaft position sensor (TDC) Engine speed
Ignition switch Start signal
When the ECM receives a start signal from the ignition switch,
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 the specific value, and shifts the control to the normal
or idle control.
Idle control
Input/output signal chart
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection con-
trol (Idle control)Electronic control fuel injec-
tion pump Crankshaft position sensor (TDC) Engine speed
Park/Neutral position (PNP) switch Gear position
Battery Battery voltage
Accelerator position switch Idle position
Vehicle speed sensor Vehicle speed
Air conditioner switch Air conditioner signal
Intake air temperature sensor Intake air temperature
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. The ECM also provides the system with a fast idle control in response
to the engine coolant temperature and heat up switch signal.
SEF648S
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTIONYD25DDTi
EC-3411

Normal control
Input/output signal chart
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor (TDC) Engine speed
Fuel injection con-
trol (Normal con-
trol)Electronic control fuel injec-
tion pump Accelerator position sensor Accelerator position
Vehicle speed sensor 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.
Maximum amount control
Input/output signal chart
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection con-
trol (Maximum
amount control)Electronic control fuel injec-
tion pump Crankshaft position sensor (TDC) Engine speed
Accelerator position sensor Accelerator position
The maximum injection amount is controlled to an optimum by the engine speed, intake air amount, engine
coolant temperature, and accelerator opening in accordance with the driving conditions.
This prevents the oversupply of the injection amount caused by decreased air density at a high altitude or
during a system failure.
Deceleration control
Input/output signal chart
Sensor Input Signal to ECM ECM Function Actuator
Accelerator position switch Accelerator positionFuel injection con-
trol (Deceleration
control)Electronic control fuel injec-
tion pump
Crankshaft position sensor (TDC) Engine speed
The ECM sends a fuel cut signal to the electronic control fuel injection pump during deceleration for better
fuel efficiency. The ECM determines the time of deceleration according to signals from the accelerator posi-
tion switch and crankshaft position sensor (TDC).
SEF649S
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTIONYD25DDTi
Fuel Injection Control System (Cont'd)
EC-3412

Fuel Injection Timing Control System
DESCRIPTION
The target fuel injection timing in accordance with the engine speed and the fuel injection amount are
recorded as a map in the ECM beforehand. The ECM and the injection pump control unit exchange signals
and perform feedback control for optimum injection timing in accordance with the map.
Air Conditioning Cut Control
DESCRIPTION
Input/output signal chart
Sensor Input Signal to ECM ECM Function Actuator
Air conditioner switch Air conditioner ªONº signal
Air conditioner cut
controlAir conditioner relay Accelerator position sensor Accelerator position
Vehicle speed sensor Vehicle speed
Engine coolant temperature sensor Engine 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 engine coolant temperature returns to normal.
Fuel Cut Control (at no load & high engine
speed)
DESCRIPTION
Input/output signal chart
Sensor Input Signal to ECM ECM Function Actuator
Vehicle speed sensor Vehicle speed
Fuel cut controlElectronic control fuel injec-
tion pump Park/Neutral position (PNP) switch Neutral position
Accelerator position switch Accelerator position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (TDC) Engine speed
If the engine speed is above 2,700 rpm with no load (for example, in neutral and engine speed over 2,700
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 operate until the engine speed reaches 1,500 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under ªFuel Injection Control Systemº,
EC-3411.
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTIONYD25DDTi
EC-3413

Spray Pattern Test
1. Check spray pattern by pumping tester handle one full stroke
per second.
NG spray pattern:
Does not inject straight and strong (B in the fig-
ure).
Fuel drips (C in the figure).
Does not inject evenly (D in the figure).
2. If the spray pattern is not correct, replace injection nozzle
assembly.
Electronic Control Fuel Injection Pump
REMOVAL AND INSTALLATION
Removal
1. Remove the parts shown below.
+Engine hood
+Engine coolant (drain)
+Engine cover
+Heater pipe under intake manifold
+Injection tubes
+Right splash cover (with undercover)
+Right front wheel
SEF434Z
JEC336D
BASIC SERVICE PROCEDUREYD25DDTi
Injection Tube and Injection Nozzle (Cont'd)
EC-3419

ENGINE CONTROL COMPONENT PARTS/CONTROL
SYSTEMS APPLICATION
ItemDIAGNOSTIC TEST MODE
SELF-DIAG
RESULTSDATA MONI-
TORACTIVE
TEST
ENGINE CONTROL COMPONENT PARTS
INPUTEngine coolant temperature sensor X X
Intake air temperature sensor X X
Vehicle speed sensor X X
Accelerator position sensor X X X
Accelerator position switch X X
Crankshaft position sensor (TDC) X X
Ignition switch (start signal) X
Park/Neutral position (PNP) switch X
Battery voltage X
Air conditioner switch X
Brake pedal position switch X X
Charge air pressure sensor X X
Heat up switch X
Stop lamp switch X X
OUTPUTGlow relayXX
EGR volume control valve X X X
Cooling fan relay X X X
Air conditioner relay X
X: Applicable
SELF-DIAGNOSTIC MODE
Regarding items detected in ªSELF-DIAG RESULTSº mode,
refer to ªTROUBLE DIAGNOSIS Ð INDEXº, EC-3400.
DATA MONITOR MODE
Monitored item
[Unit]ECM
input
signalsMain
signalsDescription Remarks
CKPSzRPM (TDC)
[rpm]jj+The engine speed computed from the
crankshaft position sensor (TDC) signal
is displayed.
CMPSzRPMzPUMP
[rpm]jj+The engine speed computed from the
pulse signal sent from electronic control
fuel injection pump is displayed.
COOLAN TEMP/S
[ÉC] or [ÉF]
jj+The engine coolant temperature (deter-
mined by the signal voltage of the
engine coolant temperature sensor) is
displayed.+When the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine cool-
ant temperature determined by the ECM
is displayed.
VHCL SPEED SE
[km/h] or [mph]jj+The vehicle speed computed from the
vehicle speed sensor signal is displayed.
FUEL TEMP SEN
[ÉC] or [ÉF]jj+The fuel temperature (sent from elec-
tronic control fuel injection pump) is dis-
played.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONYD25DDTi
CONSULT-II (Cont'd)
EC-3435

SYSTEM Ð Basic engine control sys-
temSYMPTOM
Reference page
Feature of symptom, Check pointROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEAT/HIGH ENGINE COOLANT TEMPERATURE
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
ABNORMAL SMOKE COLOR
DEAD BATTERY (UNDER CHARGE)
Malfunction indicator lamp illuminates.
Can be detected by CONSULT-II?
Fuel cutBLACK SMOKE
WHITE SMOKEWarranty symptom code AG AH AJ AK AL AM AP HA
Electronic control fuel injection pump
mainframe443 4 54 333 Ð *1
Injection nozzle 3 3 3 4 3 1 EC-3415 *2
Glow system 1 EC-3622
Engine body 3 3 3 3 3 3 EM section *3
EGR system 3 EC-3606
Air cleaner and ducts 3 3 MA section *4
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*1: Fuel injection system malfunction or fuel injection timing control system malfunction may be the cause.
*2: Depends on open-valve pressure and spray pattern.
*3: Caused mainly by insufficient compression pressure.
*4: Symptom varies depending on off-position of air duct, etc.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONYD25DDTi
Symptom Matrix Chart (Cont'd)
EC-3451

SYSTEM Ð ENGINE CONTROL system
Malfunction
SYMPTOM
Reference page
Feature of symptom, Check pointHARD/NO START/RESTART
(EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
KNOCK/DETONATION
LACK OF POWER
POOR ACCELERATION
HI IDLE
LOW IDLE NO START (with first firing)
NO START (without first firing)
HARD TO START WHEN ENGINE IS COLD
HARD TO START WHEN ENGINE IS HOT
AT IDLE
DURING DRIVING
WHEN DECELERATINGWarranty symptom code AA AB AC AD AE AF
ENGINE CONTROL
Electronic control fuel injection pump
circuit*a, *b 1 1
111111111
Ð
*c, *d
Engine coolant temperature sensor
circuit*a, *b 1 1 1 1 EC-3481 *1
Vehicle speed sensor circuit *a, *b 1 EC-3485
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*1: Compensation according to engine coolant temperature does not function.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONYD25DDTi
Symptom Matrix Chart (Cont'd)
EC-3452

SYSTEM Ð ENGINE CONTROL system
Malfunction
SYMPTOM
Reference page
Feature of symptom, Check pointROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEAT/HIGH ENGINE COOLANT TEMPERATURE
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
ABNORMAL SMOKE COLOR
DEAD BATTERY (UNDER CHARGE)
Malfunction indicator lamp illuminates.
Can be detected by CONSULT-II?
Fuel cutBLACK SMOKE
WHITE SMOKEWarranty symptom code AG AH AJ AK AL AM AP HA
ENGINE CONTROL
Electronic control fuel injection pump
circuit*a, *b 1 1 1
111
Ð
*c, *d 1
Engine coolant temperature sensor
circuit*a, *b 1 1 1 1 1 EC-3481 *1
Vehicle speed sensor circuit *a, *b 1 EC-3485
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*1: Compensation according to engine coolant temperature does not function.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONYD25DDTi
Symptom Matrix Chart (Cont'd)
EC-3453