2001 NISSAN X-TRAIL coolant

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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EC
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-1416
[YD]
TROUBLE DIAGNOSIS
Symptom Matrix Chart
EBS0037F
SYSTEM — Basic engine control systemSYMPTOM
Reference page
HARD/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 I D L E DURING DRIVING WHEN DECELERATING
Warranty symptom code AA AB AC AD AE AF
Fuel supply pump 5 5 5 5 5 5 5 5 5 5 5 —
Fuel injector 3 3 3 3 3 3 3 3 3 4 4 3 3EC-1472
EDU (Electronic drive unit) 4 4 4 4 4 4 4 4 4 5 5 4 4EC-1501
Glow control system 1 1 1 1 1EC-1544
Engine body 3 3 3 3 3 3 3 3 4 4 3EM-110
EGR system33EC-1551
Air cleaner and duct33MA-32
Fuel pressure relief valveEC-1405
ENGINE CONTROL
Suction control valve circuit 4 4 4 4 4 4 4 4 4 4 4EC-1519
Fuel injector circuit 1 1 1 1 1 1 1 1 1 1 1 1 1EC-1472
EDU circuit 2222222222222EC-1501
Mass air flow sensor circuit 1 1 1EC-1451
Engine coolant temperature circuit 1 1 1 1EC-1456
Vehicle speed sensor circuit 1EC-1489
Accelerator pedal position sensor circuit 1 1 1EC-1460
Accelerator pedal released position
switch circuit111111EC-1531
Common rail fuel pressure sensor
circuitEC-1468
Crankshaft position sensor (TDC)
circuit1111111111EC-1479

EC-1418
[YD]
TROUBLE DIAGNOSIS
SYSTEM — Basic engine control systemSYMPTOM
Reference page
ROUGH 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 illuminates. Can be detected by CONSULT-II?
BLACK SMOKE WHITE SMOKE
Warranty symptom code AG AH AJ AK AL AM AP HA
Fuel supply pump 5 5 5 5 1 1 —
Fuel injector 3 3 3 4 4 4 1 1EC-1472
EDU (Electronic drive unit) 4 4 4 5 5 5 1 1EC-1501
Glow system1EC-1544
Engine body 3 3 3 3 1 3EM-110
EGR system3EC-1551
Air cleaner and duct3MA-32
Fuel pressure relief valveEC-1405
ENGINE CONTROL
Suction control valve circuit 4 4 4 4 1 1EC-1519
Fuel injector circuit 1 1 1 1 1 1 1 1EC-1472
EDU circuit 2 2 2 2 2 2 1 1EC-1501
Mass air flow sensor circuit 1 1 1EC-1451
Engine coolant temperature circuit 1 1 1 1 1EC-1456
Vehicle speed sensor circuit11EC-1489
Accelerator pedal position sensor circuit 1 1 1EC-1460
Accelerator pedal released position switch
circuit11EC-1531
Common rail fuel pressure sensor
circuit11EC-1468
Crankshaft position sensor (TDC)
circuit11 11EC-1479

TROUBLE DIAGNOSIS
EC-1419
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EC
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
ENGINE CONTROL
Camshaft position sensor circuitEC-1484
Start signal circuitEC-1566
Ignition switch circuitEC-1442
Power supply for ECM circuit11EC-1442
Cooling fan relay circuit 2EC-1508
EGR volume control valve circuit 1EC-1551
Glow relay circuit1EC-1544
ECM relay (Self-shutoff) circuit1EC-1538
ECM, connector circuit 2 2 2 2 2 2 2 2 2 2 2EC-1494,EC-
1536
Air conditioner relay circuitEC-1572
Air conditioner switch circuitEC-1572
NATS (Nissan Anti-theft System)1EC-1406
SYSTEM — Basic engine control systemSYMPTOM
Reference page
ROUGH 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 illuminates. Can be detected by CONSULT-II?
BLACK SMOKE WHITE SMOKE
Warranty symptom code AG AH AJ AK AL AM AP HA

EC-1426
[YD]
TROUBLE DIAGNOSIS
TERMI-
NAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse Signal)
A1
A2
A3
A4L/W
Y/PU
PU
YEDU drive No. 2
EDU drive No. 4
EDU drive No. 3
EDU drive No. 1[Engine is running]
●Warm-up condition
●Idle speed0 - 4V
[Engine is running]
●Warm-up condition
●Engine speed is 2,000 rpm0 - 4V
A5
A6
A7B
B
BECM ground[Engine is running]
●Idle speedApproximately 0V
A8
A9R
RPower supply for ECM[Ignition switch “ON”]BATTERY VOLTAGE
(11 - 14V)
A10 R Mass air flow sensor[Engine is running]
●Warm-up condition
●Idle speed0.5 - 2.5V
[Engine is running]
●Warm-up condition
●Engine speed is 2,000 rpm1.5 - 3.5V
A11 L/OREngine coolant tempera-
ture sensor[Engine is running]
●Warm-up conditionApproximately 0 - 4.8V
Output voltage varies with engine
coolant temperature
A12 PU Fuel temperature sensor[Engine is running]
●Warm-up conditionApproximately 0 - 4.8V
Output voltage varies with fuel
temperature
A21 BAccelerator pedal
released position switch
ground[Ignition switch “ON”]Approximately 0V
A22 LGAccelerator pedal position
sensor 1 ground[Ignition switch “ON”]Approximately 0V
A23 B Sensor's ground[Engine is running]
●Warm-up condition
●Idle speedApproximately 0V
PBIB0387E
PBIB0388E
PBIB0389E
PBIB0390E

TROUBLE DIAGNOSIS
EC-1433
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ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
X: Applicable
SELF-DIAGNOSTIC MODE
Regarding items detected in “SELF-DIAG RESULTS” mode, refer to — EC-1393, "INDEX FOR DTC" .
DATA MONITOR MODE
ItemDIAGNOSTIC TEST MODE
SELF-DIAG
RESULTSDATA MONI-
TORACTIVE
TEST
ENGINE CONTROL COMPONENT PARTS
INPUTCrankshaft position sensor (TDC)××
Camshaft position sensor×
Engine coolant temperature sensor××
Vehicle speed sensor××
Fuel temperature sensor××
Accelerator pedal position sensor 1××
Accelerator pedal position sensor 2××
Accelerator pedal released position switch××
Common rail fuel pressure sensor××
Park/neutral position (PNP) switch×
Mass air flow sensor××
Battery voltage××
Power steering oil pressure switch×
Stop lamp switch×
Absolute pressure sensor××
Fuel injector adjustment resistor×
OUTPUTSuction control valve×××
Fuel injector×××
Glow relay××
Cooling fan relay×××
EGR volume control valve××
MONITOR ITEMECM
INPUT
SIG-
NALMAIN
SIG-
NALSCAN
DIAG
SUP-
PORT
MNTRCONDITION SPECIFICATION
CKPS·RPM (TDC) [rpm]××
●The engine speed computed
from the crankshaft position
sensor (TDC) signal is dis-
played.
COOLAN TEMP/S
[°C] or [°F]××
●The engine coolant tempera-
ture (determined by the signal
voltage of the engine coolant
temperature sensor) is dis-
played.When the engine coolant temper-
ature circuit is open or short, ECM
enters fail-safe mode. The engine
coolant temperature determined
by the ECM is displayed.
VHCL SPEED SE
[km/h] or [mph]××
●The vehicle speed computed
form the vehicle speed sensor
signal is displayed.
FUEL TEMP SEN [°C] or [°F]××
●The fuel temperature (deter-
mined by the signal voltage of
the fuel temperature sensor) is
displayed.

EC-1456
[YD]
DTC P0115 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (CIRCUIT)
DTC P0115 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (CIRCUIT)
PFP:22630
DescriptionEBS004Q8
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.

*: These data are reference values and measured between ECM terminal A11
(Engine coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis LogicEBS004Q9
DTC Confirmation ProcedureEBS004QA
WITH CONSULT-II
1. Turn ignition switch “ON”.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If DTC is detected, go to EC-1458, "
Diagnostic Procedure" .
SEF594K
Engine coolant tempera-
ture °C (°F)Voltage* (V) Resistance (kΩ)
−10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.3 0.68 - 1.00
90 (194) 1.0 0.236 - 0.260
SEF012P
DTC Malfunction is detected when ... Check Items (Possible Cause)
P0115
●An excessively high or low voltage from the sensor
is sent to ECM.●Harness or connectors
(The sensor circuit is open or shorted.)
●Engine coolant temperature sensor
SEF817Y