Nissan X-Trail 32. Manual - part 913

FUEL INJECTOR

EC-781

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

3.

Check resistance between fuel injector terminals as per the fol-
lowing.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace malfunctioning fuel injector. Refer to 

EM-184,

"Removal and Installation"

.

Fuel injector

Resistance

+

-

Terminal

1

2

11.1 - 14.5 

Ω

 [at 10 - 60

°

C (50 - 140

°

F)]

PBIA9579J

EC-782

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

FUEL PUMP

FUEL PUMP

Description

INFOID:0000000010986490

*: 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
start ability. If the ECM receives a engine speed signal from the camshaft 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 Function Check

INFOID:0000000010986491

1.

CHECK FUEL PUMP FUNCTION

1.

Turn ignition switch ON.

2.

Pinch fuel feed hose with two fingers.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Proceed to 

EC-782, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000010986492

1.

CHECK FUEL PUMP RELAY CONTROL SIGNAL

1.

Turn ignition switch ON.

2.

Check the voltage between ECM harness connector.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 2.

2.

CHECK FUEL PUMP RELAY CONTROL SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Disconnect IPDM E/R harness connector.

Sensor

Input signal to ECM

ECM Function

Actuator

Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)

Engine speed*

Fuel pump control

Fuel pump relay

↓

Fuel pump

Battery

Battery voltage*

Condition

Fuel pump operation

Ignition switch is turned to ON.

Operates for 1 second.

Engine running and cranking

Operates.

When engine is stopped

Stops in 1.5 seconds.

Except as shown above

Stops.

Fuel pressure pulsation should be felt on the fuel feed 
hose for 1 second after ignition switch is turned ON.

ECM

Voltage

+

-

Connector

Terminal

Connector

Terminal

F85

18

E60

128

Battery voltage should exist 1 second after 
ignition switch is turn ON.

FUEL PUMP

EC-783

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

4.

Check the continuity between ECM harness connector and IPDM E/R harness connector.

5.

Also check harness for short to ground and to power.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Repair or replace error-detected parts.

3.

CHECK FUEL PUMP POWER SUPPLY

1.

Turn ignition switch OFF.

2.

Disconnect “fuel level sensor unit and fuel pump” harness connector.

3.

Turn ignition switch ON.

4.

Check the voltage between “fuel level sensor unit and fuel pump” harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

CHECK FUEL PUMP POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect IPDM E/R harness connector.

3.

Check the continuity between IPDM E/R harness connector and “fuel level sensor unit and fuel pump”
harness connector.

4.

Also check harness for short to ground and to power.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Repair or replace error-detected parts.

5.

CHECK FUEL PUMP GROUND CIRCUIT

1.

Check the continuity between “fuel level sensor unit and fuel pump” and ground. 

2.

Also heck harness for short to power. 

Is the inspection result normal?

+

-

Continuity

ECM

IPDM E/R

Connector

Terminal

Connector

Terminal

F85

18

F72

76

Existed

+

-

Voltage

Fuel level sensor unit 

and fuel pump

Connector

Terminal

B40

1

Ground

Battery voltage should exist 1 second 
after ignition switch is turn ON.

+

-

Continuity

IPDM E/R

Fuel level sensor unit and 

fuel pump

Connector

Terminal

Connector

Terminal

E11

24

B40

1

Existed

+

-

Continuity

Fuel level sensor unit and fuel pump

Connector

Terminal

B40

3

Ground

Existed

EC-784

< DTC/CIRCUIT DIAGNOSIS >

[QR25DE]

FUEL PUMP

YES

>> GO TO 6.

NO

>> Repair or replace error-detected parts.

6.

CHECK FUEL PUMP

Refer to 

EC-784, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Replace “fuel level sensor unit and fuel pump”. Refer to 

FL-12, "Removal and Installation"

.

7.

CHECK INTERMITTENT INCIDENT

Perform 

GI-44, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace IPDM E/R. Refer to 

PCS-60, "Removal and Installation"

.

NO

>> Repair or replace harness or connectors.

Component Inspection

INFOID:0000000010986493

1.

CHECK FUEL PUMP

1.

Turn ignition switch OFF.

2.

Disconnect “fuel level sensor unit and fuel pump” harness connector.

3.

Check resistance between “fuel level sensor unit and fuel pump” terminals as follows.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace “fuel level sensor unit and fuel pump”. Refer to 

FL-12, "Removal and Installation"

.

Fuel level sensor unit and fuel pump

Resistance

+

-

Terminal

1

3

0.2 - 5.0

Ω

 [at 25

°

C (77

°

F)]