2003 NISSAN X-TRAIL width

EC-36
[QR (WITH EURO-OBD)]
ENGINE CONTROL SYSTEM


When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from heated oxygen
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from heated oxygen sensor 1 indicates whether the mixture ratio is RICH or LEAN compared
to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an
increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all four cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The four injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
SEF337W

ENGINE CONTROL SYSTEM
EC-37
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Electronic Ignition (EI) SystemEBS010LA
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The ignition timing is controlled by the ECM to maintain the best air-
fuel ratio for every running condition of the engine. The ignition tim-
ing data is stored in the ECM. This data forms the map shown.
The ECM receives information such as the injection pulse width and
camshaft position sensor signal. Computing this information, ignition
signals are transmitted to the power transistor.
e.g., N: 1,800 rpm, Tp: 1.50 msec
A °BTDC
During the following conditions, the ignition timing is revised by the
ECM according to the other data stored in the ECM.

At starting

During warm-up

At idle

At low battery voltage

During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Air Conditioning Cut ControlEBS010LB
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS)
Engine speed*
2
piston position
Ignition
timing con-
trolPower transistor Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor*1Vehicle speed
SEF742M
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch Air conditioner ON signal
Air conditioner
cut controlAir conditioner relay Throttle position sensor Throttle valve opening angle
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
2
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor*
1Vehicle speed

EC-106
[QR (WITH EURO-OBD)]
TROUBLE DIAGNOSIS

*: The items are the same as those of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×: Applicable CAL/LD VALUE [%]

The calculated load value at the moment a malfunction is detected is displayed.
COOLANT TEMP [°C]
or [°F]

The engine coolant temperature at the moment a malfunction is detected is displayed.
L-FUEL TRM-B1 [%]

“Long-term fuel trim” at the moment a malfunction is detected is displayed.

The long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule
than short-term fuel trim.
S-FUEL TRM-B1 [%]

“Short-term fuel trim” at the moment a malfunction is detected is displayed.

The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel
schedule.
ENGINE SPEED
[rpm]

The engine speed at the moment a malfunction is detected is displayed.
VEHICL SPEED [km/
h] or [mph]

The vehicle speed at the moment a malfunction is detected is displayed.
B/FUEL SCHDL
[msec]

The base fuel schedule at the moment a malfunction is detected is displayed.
INT/A TEMP SE [°C]
or [°F]

The intake air temperature at the moment a malfunction is detected is displayed. Freeze frame data
item*Description
Monitored item
[Unit]ECM
INPUT
SIGNALSMAIN
SIG-
NALSDescription Remarks
ENG SPEED [rpm]××

Indicates the engine speed computed from the
signals of the crankshaft position sensor
(POS) and camshaft position sensor (PHASE).

Accuracy becomes poor if engine
speed drops below the idle rpm.

If the signal is interrupted while the
engine is running, an abnormal
value may be indicated.
MAS A/F SE-B1 [V]××

The signal voltage of the mass air flow sensor
is displayed.
When the engine is stopped, a
certain value is indicated.
B/FUEL SCHDL
[msec]×

“Base fuel schedule” indicates the fuel injec-
tion pulse width programmed into ECM, prior
to any learned on board correction.
A/F ALPHA-B1 [%]×

The mean value of the air-fuel ratio feedback
correction factor per cycle is indicated.

When the engine is stopped, a
certain value is indicated.

This data also includes the data
for the air-fuel ratio learning con-
trol.
COOLAN TEMP/S
[°C] or [°F]××

The engine coolant temperature (determined
by the signal voltage of the engine coolant
temperature sensor) is displayed.

When the engine coolant tempera-
ture sensor is open or short-cir-
cuited, ECM enters fail-safe mode.
The engine coolant temperature
determined by the ECM is dis-
played.
HO2S1 (B1) [V]××

The signal voltage of the heated oxygen sen-
sor 1 is displayed.
HO2S2 (B1) [V]×

The signal voltage of the heated oxygen sen-
sor 2 is displayed.

EC-108
[QR (WITH EURO-OBD)]
TROUBLE DIAGNOSIS

INJ PULSE-B1
[msec]×
Indicates the actual fuel injection pulse width
compensated by ECM according to the input
signals.
When the engine is stopped, a
certain computed value is indi-
cated.
IGN TIMING
[BTDC]×

Indicates the ignition timing computed by ECM
according to the input signals.
When the engine is stopped, a
certain value is indicated.
CAL/LD VALUE [%]

“Calculated load value” indicates the value of
the current airflow divided by peak airflow.
MASS AIRFLOW
[g·m/s]

Indicates the mass airflow computed by ECM
according to the signal voltage of the mass air
flow sensor.
PURG VOL C/V
[%]

Indicates the EVAP canister purge volume
control solenoid valve control value computed
by the ECM according to the input signals.

The opening becomes larger as the value
increases.
INT/V TIM (B1)
[°CA]

Indicates [°CA] of intake camshaft advanced
angle.
INT/V SOL (B1) [%]

The control value of the intake valve timing
control solenoid valve (determined by ECM
according to the input signal) is indicated.

The advance angle becomes larger as the
value increases
VIAS S/V
[ON/OFF]

The control condition of the VIAS control sole-
noid valve (determined by ECM according to
the input signals) is indicated.
ON: VIAS control solenoid valve is operating.
OFF: VIAS control solenoid valve is not oper-
ating.
AIR COND RLY
[ON/OFF]×

The air conditioner relay control condition
(determined by ECM according to the input
signals) is indicated.
FUEL PUMP RLY
[ON/OFF]×

Indicates the fuel pump relay control condition
determined by ECM according to the input sig-
nals.
THRTL RELAY
[ON/OFF]×

Indicates the throttle control motor relay con-
trol condition determined by the ECM accord-
ing to the input signals.
COOLING FAN
[HI/LOW/OFF]

Indicates the condition of the cooling fan
(determined by ECM according to the input
signals).
HI ... High speed operation
LOW ... Low speed operation
OFF ... Stop
HO2S1 HTR (B1)
[ON/OFF]

Indicates [ON/OFF] condition of heated oxy-
gen sensor 1 heater determined by ECM
according to the input signals.
HO2S2 HTR (B1)
[ON/OFF]

Indicates [ON/OFF] condition of heated oxy-
gen sensor 2 heater determined by ECM
according to the input signals. Monitored item
[Unit]ECM
INPUT
SIGNALSMAIN
SIG-
NALSDescription Remarks

TROUBLE DIAGNOSIS
EC-109
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NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
DATA MONITOR (SPEC) MODE
Monitored Item
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.IDL A/V LEARN
[YET/CMPLT]

Display the condition of idle air volume learn-
ing
YET: Idle air volume learning has not been
performed yet.
CMPLT: Idle air volume learning has already
been performed successfully.
TRVL AFTER MIL
[km] or [mile]

Distance traveled while MI is activated.
AC PRESS SEN
[V]×

The signal voltage from the refrigerant pres-
sure sensor is displayed.
Voltage [V]

Voltage, frequency, duty cycle or pulse width
measured by the probe.

Only “#” is displayed if item is
unable to be measured.

Figures with “#”s are temporary
ones. They are the same figures
as an actual piece of data which
was just previously measured. Frequency
[msec], [Hz] or [%]
DUTY-HI
DUTY-LOW
PLS WIDTH-HI
PLS WIDTH-LOWMonitored item
[Unit]ECM
INPUT
SIGNALSMAIN
SIG-
NALSDescription Remarks
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
ENG SPEED [rpm]×

Indicates the engine speed computed
from the signals of the crankshaft posi-
tion sensor (POS) and camshaft position
sensor (PHASE).
MAS A/F SE-B1 [V]××

The signal voltage of the mass air flow
sensor specification is displayed.
When engine is running specification
range is indicated.
B/FUEL SCHDL
[msec]

“Base fuel schedule” indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.

When engine is running specification
range is indicated.
A/F ALPHA-B1 [%]×

The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.
When engine is running specification
range is indicated.

This data also includes the data for the
air-fuel ratio learning control.

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-119
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TROUBLE DIAGNOSIS - SPECIFICATION VALUEPFP:00031
DescriptionEBS010M2
The specification (SP) value indicates the tolerance of the value that is displayed in “DATA MONITOR (SPEC)”
mode of CONSULT-II during normal operation of the Engine Control System. When the value in “DATA MONI-
TOR (SPEC)” mode is within the SP value, the Engine Control System is confirmed OK. When the value in
“DATA MONITOR (SPEC)” mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:

B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)

A/F ALPHA-B1 (The mean value of air-fuel ratio feedback correction factor per cycle)

MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionEBS010M3

Vehicle driven distance: More than 5,000 km (3,017 miles)

Barometric pressure: 98.3 - 104.3 kPa (0.983 - 1.043 bar, 1.003 - 1.064 kg/cm2 , 14.25 - 15.12 psi)

Atmospheric temperature: 20 - 30°C (68 - 86°F)

Engine coolant temperature: 75 - 95°C (167 - 203°F)

Transmission: Warmed-up*1

Electrical load: Not applied*2

Engine speed: Idle
*1: For A/T models, after the engine is warmed up to normal operating temperature, drive vehicle until “FLUID
TEMP SE” (A/T fluid temperature sensor signal) indicates more than 60°C (140°F).
For M/T models, after the engine is warmed up to normal operating temperature, drive vehicle for 5 minutes.
*2: Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
Inspection ProcedureEBS010M4
NOTE:
Perform “DATA MONITOR (SPEC)” mode in maximum scale display.
1. Perform EC-79, "
Basic Inspection" .
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1” and “MAS A/F SE-
B1” in “DATA MONITOR (SPEC)” mode with CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-120, "
Diagnostic Procedure" .
SEF601Z

EC-286
[QR (WITH EURO-OBD)]
DTC P1111 IVT CONTROL SOLENOID VALVE

D T C P 1111 I V T C O N T R O L S O L E N O I D VA LV EPFP:23796
Component DescriptionEBS010R5
Intake valve timing control solenoid valve is activated by ON/OFF
pulse duty (ratio) signals from the ECM.
The intake valve timing control solenoid valve changes the oil
amount and direction of flow through intake valve timing control unit
or stops oil flow.
The longer pulse width advances valve angle.
The shorter pulse width retards valve angle.
When ON and OFF pulse widths become equal, the solenoid valve
stops oil pressure flow to fix the intake valve angle at the control
position.
CONSULT-II Reference Value in Data Monitor ModeEBS010R6
Specification data are reference values.
On Board Diagnosis LogicEBS010R7
DTC Confirmation ProcedureEBS010R8
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If 1st trip DTC is detected, go to EC-288, "
Diagnostic Procedure"
.
WITH GST
Following the procedure “WITH CONSULT-II” above.
PBIB1842E
MONITOR ITEM CONDITION SPECIFICATION
INT/V SOL (B1)

Engine: After warming up

Air conditioner switch: OFF

Shift lever: N (A/T), Neutral (M/T)

No loadIdle 0% - 2%
2,000 rpm Approx. 0% - 50%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P 1111
1111Intake valve timing control
solenoid valve circuitAn improper voltage is sent to the ECM
through intake valve timing control solenoid
valve.

Harness or connectors
(Solenoid valve circuit is open or shorted.)

Intake valve timing control solenoid valve
SEF058Y

ENGINE CONTROL SYSTEM
EC-497
[QR (WITHOUT EURO-OBD)]
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*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.


During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D (A/T models)

High-load, high-speed operation


During deceleration

During high engine speed operation
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses
heated oxygen sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The
ECM adjusts the injection pulse width according to the sensor voltage signal. For more information about
heated oxygen sensor 1, refer to EC-176
. This maintains the mixture ratio within the range of stoichiometric
(ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of heated oxygen sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.

Deceleration and acceleration

High-load, high-speed operation

Malfunction of heated oxygen sensor 1 or its circuit

Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature

High engine coolant temperature

During warm-up

After shifting from N to D (A/T models)

When starting the engine
PBIB0121E