engine NISSAN X-TRAIL 2003 Service Repair Manual

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-38
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ENGINE CONTROL SYSTEM

SYSTEM DESCRIPTION
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.

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)EBS010LC
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed is 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 be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under Multiport Fuel Injection (MFI) System, EC-34
.
CAN Communication UnitEBS010LD
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.
Sensor Input Signal to ECM ECM function Actuator
Park/neutral position (PNP) switch Neutral position
Fuel cut control Fuel injector Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed
Wheel sensor* Vehicle speed

ENGINE CONTROL SYSTEM
EC-39
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M/T MODELS WITHOUT ESP
System Diagram
Input/output Signal Chart
T: Transmit R: Receive
PKIA6458E
Signals ECMABS actuator and
electric unit (con-
trol unit)4WD control unit Combination meter
Stop lamp switch signal T R
Engine speed signal T R R
Engine coolant temperature signal T R
Accelerator pedal position signal T R
A/C compressor feedback signal T R
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signal T R
Parking brake switch signalRT
MI signal T R

EC-40
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ENGINE CONTROL SYSTEM

A/T MODELS WITHOUT ESP
System Diagram
Input/output Signal Chart
T: Transmit R: Receive
PKIA6457E
Signals ECM TCMABS actuator
and electric unit
(control unit)4WD control
unitCombination
meter
Stop lamp switch signalRT
TR
P·N range signal R T
A/T position indicator lamp signal T R
Overdrive control switch signal R T
O/D OFF indicator signal T R
Closed throttle position signal T R
Wide open throttle position signal T R
Engine speed signal T R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R
Output shaft revolution signal R T
A/C compressor feedback signal TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Engine A/T integrated control signalTR
RT
A/T self-diagnosis signal R T

ENGINE CONTROL SYSTEM
EC-41
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M/T MODELS WITH ESP
System Diagram
Input/output Signal Chart
T: Transmit R: Receive
*1: YD engine models only
*2: QR engine models only
PKIA6459E
Signals ECMESP/TCS/ABS
control unitSteering angle
sensor4WD control
unitCombination
meter
Stop lamp switch signal T R
Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
A/C switch signal*
1RT
A/C compressor feedback signal*
2TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
Brake warning lamp signal T R
SLIP indicator lamp signal T R
ESP OFF indicator lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Glow indicator lamp signal*
1TR
Steering angle sensor signal R T

EC-42
[QR (WITH EURO-OBD)]
ENGINE CONTROL SYSTEM

A/T MODELS WITH ESP
System Diagram
Input/output Signal Chart
T: Transmit R: Receive
PKIA6460E
Signals ECM TCMESP/TCS/
ABS control
unitSte ering
angle sensor4WD control
unitCombination
meter
Stop lamp switch signalRT
TR
P·N range signal R T
A/T position indicator lamp signal T R R
O/D OFF indicator signal T R
Overdrive control switch signal R T
Closed throttle position signal T R
Wide open throttle position signal T R
Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
Output shaft revolution signal R T
A/C compressor feedback signal TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
Brake warning lamp signal T R
SLIP indicator lamp signal T R
ESP OFF indicator lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Steering angle sensor signal R T

ENGINE CONTROL SYSTEM
EC-43
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Engine and A/T integratedTR
RT
A/T self-diagnosis signal R TSignals ECM TCMESP/TCS/
ABS control
unitSteering
angle sensor4WD control
unitCombination
meter

EC-46
[QR (WITH EURO-OBD)]
BASIC SERVICE PROCEDURE

3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
Throttle Valve Closed Position LearningEBS010LG
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.
3. Turn ignition switch OFF and wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume LearningEBS010LH
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
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 - 95°C (158 - 203°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-45, "Accelerator Pedal Released Position Learning" .
2. Perform EC-46, "
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.
SEF217Z

BASIC SERVICE PROCEDURE
EC-47
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6. Touch “START” and wait 20 seconds.
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-45, "
Accelerator Pedal Released Position Learning" .
2. Perform EC-46, "
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 5 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 turned ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
SEF454Y
ITEM SPECIFICATION
Idle speed QR20DE with M/T models: 650±50 rpm (in Neutral position)
Except above: 700±50 rpm [in P or N (A/T), Neutral (M/T) position]
Ignition timing M/T: 15±5° BTDC (in Neutral position)
A/T: 15±5° BTDC (in P or N position)
MBIB0238E
PBIB0665E

EC-48
[QR (WITH EURO-OBD)]
BASIC SERVICE PROCEDURE

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 carried
out successfully. In this case, find the cause of the incident by referring to the DIAGNOSTIC PROCE-
DURE below.
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-119, "
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 CheckEBS010LI
FUEL PRESSURE RELEASE
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 2 or 3 times to release all fuel pres-
sure.
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 2 or 3 times to release all fuel pres-
sure.
4. Turn ignition switch OFF.
5. Reinstall fuel pump fuse after servicing fuel system.
FUEL PRESSURE CHECK
Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.
ITEM SPECIFICATION
Idle speed QR20DE with M/T models: 650±50 rpm (in Neutral position)
Except above: 700±50 rpm [in P or N (A/T), Neutral (M/T) position]
Ignition timing M/T: 15±5° BTDC (in Neutral position)
A/T: 15±5° BTDC (in P or N position)
SEF214Y
PBIB0508E