Nissan Altima L32. Manual - part 336

FUEL INJECTOR

EC-465

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

C

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E

F

G

H

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A

EC

N

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O

2. Disconnect fuel injector harness connector.

3. Check resistance between fuel injector terminals as follows.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace malfunctioning fuel injector.

Terminals

Resistance

1 and 2

11.1 - 14.3 

Ω [at 10 -60°C (50 - 140°F)]

JMBIA1637ZZ

EC-466

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

FUEL PUMP

FUEL PUMP

Description

INFOID:0000000004349528

*: 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:0000000004349529

1.

CHECK FUEL PUMP FUNCTION

1. Turn ignition switch ON.

2. Pinch fuel feed hose (2) with two fingers.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>>

EC-466, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000004349530

1.

CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Turn ignition switch ON.

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.

1

: Air cleaner assembly

: Vehicle front

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

ALBIA0080ZZ

FUEL PUMP

EC-467

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

4. Check the voltage between ECM harness connector and

ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 2.

2.

CHECK FUEL PUMP POWER SUPPLY CIRCUIT-II

1. Turn ignition switch OFF.

2. Disconnect IDPDM E/R harness connector F10.

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

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair open circuit or short to ground or short to power in harness or connectors.

3.

CHECK CONDENSER-1 POWER SUPPLY CIRCUIT-I

1. Reconnect all harness connectors disconnected.

2. Disconnect condenser-1 harness connector.

3. Turn ignition switch ON.

4. Check the voltage between condenser-1 harness connector and

ground.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

CHECK 15A FUSE

1. Turn ignition switch OFF.

2. Disconnect 15A fuse (No. 32) from IPDM E/R.

3. Check 15A fuse.
Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Replace fuse.

5.

CHECK CONDENSER-1 POWER SUPPLY CIRCUIT-II

1. Disconnect IPDM E/R harness connector E18.

2. Check the continuity between IPDM E/R harness connector and condenser-1 harness connector.

3. Also check harness for short to ground and short to power.

ECM

Ground

Voltage

Connector Terminal

F14

14

Ground Battery voltage

PBIB3605E

ECM

IPDM E/R

Continuity

Connector Terminal Connector Terminal

F14

14

F10

77

Existed

Condenser-1

Ground

Voltage

Connector

Terminal

B17

1

Ground

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

PBIB0624E

IPDM E/R

Condenser-I

Continuity

Connector Terminal

Connector Terminal

F18

13

B17

1

Existed

EC-468

< COMPONENT DIAGNOSIS >

[QR25DE FOR CALIFORNIA]

FUEL PUMP

Is the inspection result normal?

YES

>> GO TO 13.

NO

>> GO TO 7.

6.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors E29, B10

• IPDM E/R connector F10

• Harness for open or short between IPDM E/R and condenser-I

>> Repair open circuit or short to power in harness or connectors.

7.

CHECK CONDENSER GROUND CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect dropping resistor harness connector.

3. Check the continuity between condenser-I harness connector and ground.

4. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Repair open circuit or short to power in harness or connectors.

8.

CHECK CONDENSER-1

Refer to 

EC-469, "Component Inspection (Condenser-1)"

.

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> Replace condenser-1.

9.

CHECK FUEL PUMP POWER SUPPLY CIRCUIT-III

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

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

ground. 

Is the inspection result normal?

YES

>> GO TO 11.

NO

>> GO TO 10.

10.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connector E29, B10

• Harness for open or short between “fuel level sensor unit and fuel pump” and IPDM E/R

• Harness for open or short between “fuel level sensor unit and fuel pump” and ground

>> Repair open circuit or short to power in harness or connectors.

11.

CHECK FUEL PUMP GROUND CIRCUIT

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

Condenser-I

Ground

Continuity

Connector

Terminal

B17

2

Ground

Existed

IPDM E/R

Fuel level sensor unit 

and fuel pump

Continuity

Connector Terminal

Connector Terminal

E18

13

B42

1

Existed