2003 NISSAN X-TRAIL start

FUEL PUMP CIRCUIT
EC-443
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FUEL PUMP CIRCUITPFP:17042
DescriptionEBS010VH
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine
startability. If the ECM receives a engine speed signal from the crankshaft position sensor (POS) and cam-
shaft position sensor (PHASE), it knows that the engine is rotating, and causes the pump to operate. If the
engine speed signal is not received when the ignition switch is ON, the engine stalls. The ECM stops pump
operation and prevents battery discharging, thereby improving safety. The ECM does not directly drive the fuel
pump. It controls the ON/OFF fuel pump relay, which in turn controls the fuel pump.
COMPONENT DESCRIPTION
A turbine type design fuel pump is used in the fuel tank.
CONSULT-II Reference Value in Data Monitor ModeEBS010VI
Specification data are reference values.
Sensor Input Signal to ECM ECM Function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
Fuel pump control Fuel pump relay
Battery Battery voltage*
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and crankingOperates.
When engine is stoppedStops in 1.5 seconds.
Except as shown aboveStops.
PBIB0513E
MONITOR ITEM CONDITION SPECIFICATION
FUEL PUMP RLY

For 1 second after turning ignition switch ON

Engine running or crankingON

Except above conditions OFF

REFRIGERANT PRESSURE SENSOR
EC-453
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Specification data are reference values and are measured between each terminal 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.
Diagnostic ProcedureEBS010VP
1. CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower switch ON.
3. Check voltage between ECM terminal 69 and ground with CON-
SULT-II or tester.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
46 RSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V
57 BSensor ground
(Intake air temperature
sensor/ Power steering
pressure sensor/ Refriger-
ant pressure sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
69 YRefrigerant pressure sen-
sor[Engine is running]

Warm-up condition

Both A/C switch and blower switch are ON
(Compressor operates)1.0 - 4.0V
Voltage: 1.0 - 4.0V
MBIB0035E

EC-464
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ELECTRICAL LOAD SIGNAL

Specification data are reference values and are measured between each terminal 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.
Diagnostic ProcedureEBS010VU
1. INSPECTION START
Do you have CONSULT-II?
Ye s o r N o
Yes >> GO TO 2.
No >> GO TO 3.
2. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCITION-I
With CONSULT-II
1. Turn ignition switch ON.
2. Check “LOAD SIGNAL” in “DATA MONITOR” mode with CON-
SULT-II under the following conditions.
OK or NG
OK >> GO TO 4.
NG >> GO TO 8.
3. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 84 and ground under the
following conditions.
OK or NG
OK >> GO TO 5.
NG >> GO TO 8.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
93 BRElectrical load signal
(Rear window defogger
signal)[Ignition switch: ON]

Rear window defogger switch: ONBATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]

Rear window defogger switch: OFFApproximately 0V
Condition LOAD SIGNAL
Lighting switch: ON at 2nd position ON
Lighting switch: OFF OFF
PBIB0103E
Condition Voltage
Lighting switch: ON at 2nd position BATTERY VOLTAGE
Lighting switch: OFF 0V
MBIB0158E

EC-466
[QR (WITH EURO-OBD)]
ELECTRICAL LOAD SIGNAL

8. CHECK HEADLAMP FUNCTION
1. Start engine.
2. Turn the lighting switch ON at 2nd position.
3. Check that headlamps are illuminated.
OK or NG
OK >> GO TO 9.
NG >> Refer to LT- 4 , "
HEADLAMP" or LT- 2 0 , "HEADLAMP - DAYTIME LIGHT SYSTEM -" .
9. CHECK HEADLAMP INPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Stop engine.
2. Disconnect ECM harness connector.
3. Disconnect lighting switch harness connectors.
4. Check harness continuity between lighting switch terminal 9, 10 and ECM terminal 84 under the following
conditions.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 16.
NG >> GO TO 10.
10. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E106, M14 (LHD models)

Harness connectors E105, M13 (RHD models)

Diode E123

Diode E124

Harness for open and short between lighting switch and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
Condition Continuity
1 Should exist
2 Should not exist
PBIB1994E

ELECTRICAL LOAD SIGNAL
EC-467
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11 . CHECK REAR WINDOW DEFOGGER FUNCTION
1. Start engine.
2. Turn ON the rear window defogger switch.
3. Check the rear windshield. Is the rear windshield heated up?
Ye s o r N o
Ye s > > G O T O 1 2 .
No >> Refer to GW-17, "
REAR WINDOW DEFOGGER" .
12. CHECK REAR WINDOW DEFOGGER INPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Stop engine.
2. Disconnect ECM harness connector.
3. Disconnect rear window defogger relay.
4. Check harness continuity between rear window defogger relay 3 (without door mirror defogger), 5 (with
door mirror defogger) and ECM terminal 93.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 16.
NG >> GO TO 13.
13. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors B1, M17

Harness for open and short between rear window defogger relay and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
14. CHECK HEATER FAN CONTROL FUNCTION
1. Start engine.
2. Turn ON the fan control switch.
3. Check the blower fan motor. Does the blower fan motor activate?
Ye s o r N o
Ye s > > G O T O 1 5 .
No >> Refer to AT C - 3 4 , "
TROUBLE DIAGNOSIS" or MTC-3, "TROUBLE DIAGNOSIS" .
15. CHECK HEATER FAN SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Stop engine.
2. Disconnect ECM harness connector.
3. Disconnect A/C AUTO AMP. harness connector.
4. Check harness continuity between A/C AUTO AMP. terminal 19 and ECM terminal 96.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 16.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.Continuity should exist.
Continuity should exist.

PRECAUTIONS
EC-487
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Do not disassemble ECM.

If battery cable is disconnected, the memory will return to
the initial ECM values.
The ECM will now start to self-control at its initial values.
Engine operation can vary slightly when the cable is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not replace parts because of a slight variation.

When connecting ECM harness connector, fasten it
securely with levers as far as they will go as shown in the
figure.

When connecting or disconnecting pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM
pin terminal, when connecting pin connectors.

Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge)
voltage to develop in coil and condenser, thus resulting in
damage to ICs.

Keep engine control system harness at least 10 cm (4 in)
away from adjacent harness, to prevent engine control sys-
tem malfunctions due to receiving external noise, degraded
operation of ICs, etc.

Keep engine control system parts and harness dry.

Before replacing ECM, perform ECM Terminals and Refer-
ence Value inspection and make sure ECM functions prop-
erly. Refer to EC-543
.

Handle mass air flow sensor carefully to avoid damage.

Do not disassemble mass air flow sensor.

Do not clean mass air flow sensor with any type of deter-
gent.

Do not disassemble electric throttle control actuator.

Even a slight leak in the air intake system can cause seri-
ous incidents.

Do not shock or jar the camshaft position sensor (PHASE),
crankshaft position sensor (POS).
PBIB1164E
PBIB1512E
PBIB0090E
MEF040D

PRECAUTIONS
EC-489
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Do not depress accelerator pedal when starting.

Immediately after starting, do not rev up engine unneces-
sarily.

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 standing-
wave radio can be kept smaller.
–Be sure to ground the radio to vehicle body.
Wiring Diagrams and Trouble DiagnosisEBS010WJ
When you read wiring diagrams, refer to the following:

GI-14, "How to Read Wiring Diagrams"

PG-2, "POWER SUPPLY ROUTING" for power distribution circuit
When you perform trouble diagnosis, refer to the following:

GI-10, "HOW TO FOLLOW TEST GROUPS IN TROUBLE DIAGNOSES"

GI-23, "How to Perform Efficient Diagnosis for an Electrical Incident"
SEF709Y
SEF708Y

ENGINE CONTROL SYSTEM
EC-497
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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