NISSAN X-TRAIL 2001 Service Repair Manual

ENGINE CONTROL SYSTEM
EC-1131
[QR20(WITHOUT EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC
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 film) 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

EC-1132
[QR20(WITHOUT EURO-OBD)]
ENGINE CONTROL SYSTEM
Electronic Ignition (EI) System
EBS00N3I
INPUT/OUTPUT SIGNAL CHART
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 ControlEBS00N3J
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.
Sensor Input Signal to ECMECM
functionActuator
Crankshaft position sensor (POS)
Engine speed
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
Ignition switch Start signal
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery Battery voltage
Wheel sensor Vehicle 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) Engine speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor Vehicle speed

ENGINE CONTROL SYSTEM
EC-1133
[QR20(WITHOUT EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC
●When the accelerator pedal is fully depressed.
●When cranking the engine.
●At high engine speeds.
●When the engine coolant temperature becomes excessively high.
●When operating power steering during low engine speed or low vehicle speed.
●When engine speed is excessively low.
●When refrigerant pressure is excessively low or high.
Fuel Cut Control (at No Load and High Engine Speed)EBS00N3K
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm with no load (for example, in neutral and engine speed over 1,800
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 “Multiport Fuel Injection (MFI) System”, EC-
11 2 9 .
CAN CommunicationEBS00NBF
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.
FOR A/T MODELS
System diagram
Input/output signal chart
T: Transmit R: Receive Sensor Input Signal to ECMECM
functionActuator
Park/neutral position (PNP) switch Neutral position
Fuel cut
controlFuel injectors Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS) Engine speed
Wheel sensor Vehicle speed
SKIA0884E
Signals ECM TCM
Engine coolant temperature signal T R
Accelerator pedal position signal T R
A/T self-diagnosis signal R T

EC-1134
[QR20(WITHOUT EURO-OBD)]
ENGINE CONTROL SYSTEM
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

BASIC SERVICE PROCEDURE
EC-1135
[QR20(WITHOUT EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC
BASIC SERVICE PROCEDUREPFP:00018
Idle Speed and Ignition Timing CheckEBS00N3M
IDLE SPEED
With CONSULT-II
Check idle speed in “DATA MONITOR” mode with CONSULT-II.
Without CONSULT-II
Check the idle speed by installing the pulse type tachometer clamp on the loop wire or on suitable high-tension
wire which installed between No.1 ignition coil and No.1 spark plug.
NOTE:
For the method of installing the tachometer, EC-1135, "
IGNITION TIMING" .
IGNITION TIMING
Any of following two methods may be used.
●Method A
–Attach timing light to loop wire as shown.
–Check ignition timing.
●Method B
–Remove No. 1 ignition coil.
SEF058Y
PBIB0515E
PBIB0509E

EC-1136
[QR20(WITHOUT EURO-OBD)]
BASIC SERVICE PROCEDURE
–Connect No. 1 ignition coil and No. 1 spark plug with suitable
high-tension wire as shown, and attach timing light clamp to this
wire.
–Check ignition timing.
Accelerator Pedal Released Position LearningEBS00N3O
DESCRIPTION
“Accelerator Pedal Released Position Learning” is an operation to learn the fully released position of the accel-
erator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time
harness connector of accelerator pedal position sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch “ON” and wait at least 2 seconds.
3. Turn ignition switch “OFF” wait at least 10 seconds.
4. Turn ignition switch “ON” and wait at least 2 seconds.
5. Turn ignition switch “OFF” wait at least 10 seconds.
Throttle Valve Closed Position LearningEBS00N3N
DESCRIPTION
“Throttle Valve Closed Position Learning” is an operation to learn the fully closed position of the throttle valve
by monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch “ON” wait at least 10 seconds.
PBIB0516E
SEF166Y
PBIB0514E

BASIC SERVICE PROCEDURE
EC-1137
[QR20(WITHOUT EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC
3. Turn ignition switch “OFF” wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume LearningEBS00N3P
DESCRIPTION
“Idle Air Volume Learning” is an operation to learn the idle air volume that keeps each engine within the spe-
cific range. It must be performed under any of the following conditions:
●Each time electric throttle control actuator or ECM is replaced.
●Idle speed or ignition timing is out of specification.
PREPARATION
Before performing “Idle Air Volume Learning”, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
●Battery voltage: More than 12.9V (At idle)
●Engine coolant temperature: 70 - 100°C (158 - 212°F)
●PNP switch: ON
●Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting switch to the 1st position to light
only small lamps.
●Steering wheel: Neutral (Straight-ahead position)
●Vehicle speed: Stopped
●Transmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until “FLUID TEMP SE” in “DATA MONITOR” mode of “A/
T” system indicates less than 0.9V.
For A/T models without CONSULT-II and M/T models, drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-II
1. Perform EC-1136, "Accelerator Pedal Released Position Learning" .
2. Perform EC-1136, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PREPARATION” (previously mentioned) are in good order.
5. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
6. Touch “START” and wait 20 seconds.
SEF452Y
SEF454Y

EC-1138
[QR20(WITHOUT EURO-OBD)]
BASIC SERVICE PROCEDURE
7. Make sure that “CMPLT” is displayed on CONSULT-II screen. If
“CMPLT” is not displayed, “Idle Air Volume Learning” will not be
carried out successfully. In this case, find the cause of the inci-
dent by referring to the “DIAGNOSTIC PROCEDURE” below.
8. Rev up the engine two or three times and make sure that idle
speed and ignition timing are within the specifications.
Without CONSULT-II
NOTE:
●It is better to count the time accurately with a clock.
●It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
1. Perform EC-1136, "
Accelerator Pedal Released Position Learning" .
2. Perform EC-1136, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PREPARATION” (previously mentioned) are in good order.
5. Turn ignition switch “OFF” and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.
7. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MI stops
blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MI goes off.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.
13. If idle speed and ignition timing are not within the specification, “Idle Air Volume Learning” will not be car-
ried out successfully. In this case, find the cause of the incident by referring to the “DIAGNOSTIC PROCE-
DURE” below.
ITEM SPECIFICATION
Idle speed M/T: 650±50 rpm
A/T: 700±50 rpm (in “P” or “N” position)
Ignition timing M/T: 14±5° BTDC
A/T: 16±5° BTDC (in “P” or “N” position)
MBIB0238E
ITEM SPECIFICATION
Idle speed M/T: 650±50 rpm
A/T: 700±50 rpm (in “P” or “N” position)
Ignition timing M/T: 14±5° BTDC
A/T: 16±5° BTDC (in “P” or “N” position)
PBIB0665E

BASIC SERVICE PROCEDURE
EC-1139
[QR20(WITHOUT EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
MA
EC
DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:
1.Check that throttle valve is fully closed.
2.Check PCV valve operation.
3.Check that downstream of throttle valve is free from air leakage.
4.When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and eliminate the cause of the incident.
It is useful to perform EC-1188, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
5.If any of the following conditions occur after the engine has started, eliminate the cause of the
incident and perform “Idle air volume learning” all over again:
–Engine stalls.
–Erroneous idle.
Fuel Pressure CheckEBS00N3Q
FUEL PRESSURE RELEASE
Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.
With CONSULT-II
1. Turn ignition switch “ON”.
2. Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT”
mode with CONSULT-II.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch “OFF”.
Without CONSULT-II
1. Remove fuel pump fuse located in fuse box.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch “OFF”.
5. Reinstall fuel pump fuse after servicing fuel system.
FUEL PRESSURE CHECK
CAUTION:
●The fuel hose connection method used when taking fuel pressure check must not be used for
other purposes.
●Take care for not to scratch and not to put debris around connection area when servicing, so that
the quick connector keeps sealability with O-rings inside.
1. Release fuel pressure to zero. Refer to EC-1139, "
FUEL PRESSURE RELEASE" .
2. Prepare fuel hose for fuel pressure check, and connect fuel pressure gauge.
●Use suitable fuel hose for fuel pressure check (genuine NISSAN fuel hose without quick connector).
●To avoid unnecessary force or tension to hose, use moderately long fuel hose for fuel pressure check.
●Do not use the fuel hose for checking fuel pressure with damage or cracks on it.
●Use Pressure Gauge to check fuel pressure.
3. Remove fuel hose. Refer to EM-16, "
INTAKE MANIFOLD" .
SEF214Y
PBIB0508E

EC-1140
[QR20(WITHOUT EURO-OBD)]
BASIC SERVICE PROCEDURE
●Do not twist or kink fuel hose because it is plastic hose.
●Do not remove fuel hose from quick connector.
●Keep the original fuel hose to be free from intrusion of dust or foreign substances with a suitable cover.
4. Install the fuel pressure gauge as shown in the figure.
●Wipe off oil or dirt from hose insertion part using cloth moist-
ened with gasoline.
●Apply proper amount of gasoline between top of the fuel tube
and No.1 spool.
●Insert fuel hose for fuel pressure check until it touches the
No.1 spool on fuel tube.
●Use NISSAN genuine hose clamp (part number: 16439
N4710 or 16439 40U00).
●When reconnecting fuel line, always use new clamps.
●When reconnecting fuel hose, check the original fuel hose for
damage and abnormality.
●Use a torque driver to tighten clamps.
●Install hose clamp to the position within 1 - 2 mm (0.04 - 0.08
in).
●Make sure that clamp screw does not contact adjacent parts.
5. After connecting fuel hose for fuel pressure check, pull the hose
with a force of approximately 98 N (10 kg, 22 lb) to confirm fuel
tube does not come off.
6. Turn ignition switch “ON”, and check for fuel leakage.
7. Start engine and check for fuel leakage.
8. Read the indication of fuel pressure gauge.
●Do not perform fuel pressure check with system operating. Fuel pressure gauge may indicate false
readings.
●During fuel pressure check, confirm for fuel leakage from fuel connection every 3 minutes.
9. If result is unsatisfactory, go to next step.
10. Check the following.
●Fuel hoses and fuel tubes for clogging
●Fuel filter for clogging
●Fuel pump
●Fuel pressure regulator for clogging
If OK, replace fuel pressure regulator.
If NG, repair or replace.Tightening
torque: 1 - 1.5 N·m (0.1 - 0.15 kg-m, 9 - 13
in-lb)
At idling: Approximately 350 kPa (3.5 bar, 3.57 kg/cm
2 , 51
psi)
PBIB0669E
PBIB0670E