2001 NISSAN X-TRAIL engine control

EC-1396
[YD]
PRECAUTIONS
●Before replacing ECM, perform Terminals and Reference
Value inspection and make sure ECM functions properly.
Refer to EC-1425
.
●After performing each TROUBLE DIAGNOSIS, perform
“DTC Confirmation Procedure” or “Overall Function
Check”.
The DTC should not be displayed in the “ DTC Confirmation
Procedure” if the repair is completed. The “Overall Func-
tion Check” should be a good result if the repair is com-
pleted.
●When measuring ECM signals with a circuit tester, never
allow the two tester probes to contact.
Accidental contact of probes will cause a short circuit and
damage the ECM power transistor.
●Do not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use a ground other than ECM terminals, such as
the ground.
●Do not depress accelerator pedal when staring.
●Immediately after staring, do not rev up engine unnecessar-
ily.
●Do not rev up engine just prior to shutdown.
●When installing C.B. ham radio or a mobile phone, be sure
to observe the following as it may adversely affect elec-
tronic control systems depending on installation location.
–Keep the antenna as far as possible from the electronic
control units.
–Keep the antenna feeder line more than 20 cm (8 in) away
from the harness of electronic controls.
Do not let them run parallel for a long distance.
–Adjust the antenna and feeder line so that the standingwave
radio can be kept smaller.
MEF040D
SEF348N
SEF709Y
SEF708Y

EC-1398
[YD]
ENGINE CONTROL SYSTEM
ENGINE CONTROL SYSTEM
PFP:23710
System DiagramEBS0037A
PBIB1410E

ENGINE CONTROL SYSTEM
EC-1399
[YD]
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System ChartEBS0037B
*: The input signals are sent to the ECM through CAN communication line.
Fuel Injection Control SystemEBS0036G
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 adjusted to improve engine performance.
Pulse signals are exchanged between ECM and Electronic Drive Unit (EDU). EDU controls fuel injectors
according to the input signals to adjust the amount of fuel injected to the preset value.
START CONTROL
Input/Output Signal Chart
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, engine
coolant temperature and common rail fuel pressure.
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.
Input (Sensor) ECM Function Output (Actuator)
●Accelerator pedal position sensor
●Accelerator pedal released position switch
●Common rail fuel pressure sensor
●Fuel temperature sensor
●Engine coolant temperature sensor
●Crankshaft position sensor (TDC)
●Camshaft position sensor
●Vehicle speed sensor
●ESP/TCS/ABS control unit*
●Ignition switch
●Stop L amp s witch
●Air conditioner switch
●Mass air flow sensor
●Park/neutral position switch
●Battery voltage
●Power steering oil pressure switch Fuel injection controlEDU, Fuel injectors and Suction control
valve
Fuel injection timing controlEDU, Fuel injectors and Suction control
valve
Fuel cut controlEDU, Fuel injectors and Suction control
valve
Glow control system Glow relay & glow indictor lamp
On board diagnostic system Malfunction indicator (MI)
EGR volume control EGR volume control valve
Cooling fan control Cooling fan relay
Air conditioning cut control Air conditioner relay
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (start
control)EDU
Fuel injectors
Suction control valve Crankshaft position sensor (TDC) Engine speed
Camshaft position sensor Piston position
Ignition switch Start signal
Common rail fuel pressure sensor Common rail fuel pressure
SEF648S

EC-1400
[YD]
ENGINE CONTROL SYSTEM
IDLE CONTROL
Input/Output Signal Chart
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 signal.
NORMAL CONTROL
Input/Output Signal Chart
The amount of fuel injected under normal driving conditions is deter-
mined according to sensor signals. The crankshaft position sensor
(TDC) detects engine speed, the accelerator pedal position sensor
detects accelerator pedal position and common rail fuel pressure
sensor detects common rail fuel pressure. These sensors send sig-
nals to the ECM.
The fuel injection data, predetermined by correlation between vari-
ous engine speeds, accelerator pedal positions and common rail fuel
pressure are stored in the ECM memory, forming a map. The ECM
determines the optimal amount of fuel to be injected using the sen-
sor signals in comparison with the map.
MAXIMUM AMOUNT CONTROL
Input/Output Signal Chart
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 dur-
ing a system failure.
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (Idle
control)EDU
Fuel injectors
Suction control valve Crankshaft position sensor (TDC) Engine speed
Battery Battery voltage
Accelerator pedal position sensor Accelerator pedal position
Accelerator pedal released position switch Accelerator pedal released position
Vehicle speed sensor Vehicle speed
Air conditioner switch Air conditioner signal
Common rail fuel pressure sensor Common rail fuel pressure
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor (TDC) Engine speed
Fuel injection
control (Nor-
mal control)EDU
Fuel injectors
Suction control valve Accelerator pedal position sensor Accelerator position
Common rail fuel pressure sensor Common rail fuel pressure
SEF649S
Sensor Input Signal to ECM ECM Function Actuator
Mass air flow sensor Amount of intake air
Fuel injection
control (Maxi-
mum amount
control)EDU
Fuel Injectors Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (TDC) Engine speed
Accelerator pedal position sensor Accelerator position

ENGINE CONTROL SYSTEM
EC-1401
[YD]
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DECELERATION CONTROL
Input/Output Signal Chart
The ECM sends a fuel cut signal to the fuel injector and suction control valve during deceleration for better fuel
efficiency. The ECM determines the time of deceleration according to signals from the accelerator pedal
released position switch and crankshaft position sensor (TDC).
Fuel Injection Timing Control SystemEBS0036H
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 determines the optimum injection timing using sensor signals
accordance with the map.
Air Conditioning Cut ControlEBS0036I
INPUT / OUTPUT SIGNAL CHART
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 continues
until the engine coolant temperature returns to normal.
Fuel Cut Control (At No Load & High Engine Speed)EBS0036J
INPUT/OUTPUT SIGNAL CHART
If the engine speed is above 2,800 rpm with no load (for example, in neutral and engine speed over 2,800
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 EC-1399, "
Fuel Injection Control Sys-
tem" .
Sensor Input Signal to ECM ECM Function Actuator
Accelerator pedal released position switch Accelerator pedal position Fuel injection
control (Decel-
eration control)EDU
Fuel injectors
Crankshaft position sensor (TDC) Engine speed
Sensor Input Signal to ECM ECM Function Actuator
Air conditioner switch Air conditioner “ON” signal
Air conditioner
cut controlAir conditioner relay Accelerator pedal position sensor Accelerator pedal opening angle
Vehicle speed sensor Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
Sensor Input Signal to ECM ECM Function Actuator
Vehicle speed sensor Vehicle speed
Fuel cut controlEDU
Fuel injectors Accelerator pedal released position switch Accelerator position
Crankshaft position sensor (TDC) Engine speed

EC-1402
[YD]
ENGINE CONTROL SYSTEM
Crankcase Ventilation System
EBS0036K
DESCRIPTION
In this system, blow-by gas is sucked into the air duct after oil separation by oil separator in the rocker cover.
INSPECTION
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.
CAN CommunicationEBS00NBH
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
PBIB0590E
SEC692

ENGINE CONTROL SYSTEM
EC-1403
[YD]
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FOR M/T MODELS WITH ESP
System diagram
Input/output signal chart
T: Transmit R: Receive
SKIA0885E
Signals ECMSteering wheel
angle sensor4WD control unitESP/ TCS / ABS
control unit
Engine speed signal T R R
Accelerator pedal position signal T R
ESP operation signal R R T
TCS operation signal R R T
ABS operation signal R R T
Stop lamp switch signalRT
Steering wheel angle sensor signal T R
ESP-OFF switch signalRT
Wheel speed sensor signalRT
4WD mode signalTR

TROUBLE DIAGNOSIS
EC-1409
[YD]
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TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionEBS0036Z
INTRODUCTION
The engine has an ECM to control major systems such as fuel injec-
tion control, fuel injection timing control, glow control system, etc.
The ECM accepts input signals from sensors and instantly actuators.
It is essential that both input and output signals are proper and sta-
ble. At the same time, it is important that there are no malfunctions
such as vacuum leaks, or other malfunctions with the engine.
It is much more difficult to diagnose a malfunction that occurs inter-
mittently rather than continuously. Most intermittent malfunctions are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow the EC-1410, "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple on next page should be used.
Start your diagnosis by looking for “conventional” incidents first. This
will help troubleshoot driveability incidents on an electronically con-
trolled engine vehicle.
MEF036D
SEF233G
SEF234G