Infiniti Q45. Manual - part 519

FUEL PUMP

EC-715

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EC

FUEL PUMP

PFP:17042

Description

NBS0027A

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 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 DESCRIPTION

The fuel pump with a fuel pressure regulator is an in-tank type (the
pump and pressure regulator are located in the fuel tank).

CONSULT-II Reference Value in Data Monitor Mode

NBS0027B

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 5 seconds.

Engine running and cranking

Operates.

When engine is stopped

Stops in 1.5 seconds.

Except as shown above

Stops.

PBIB2462E

MONITOR ITEM

CONDITION

SPECIFICATION

FUEL PUMP RLY

●

For 5 seconds after turning ignition switch: ON

●

Engine running or cranking

ON

●

Except above

OFF

EC-716

FUEL PUMP

Wiring Diagram

NBS0027C

TBWM1257E

FUEL PUMP

EC-717

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EC

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 Procedure

NBS0027D

1. 

CHECK OVERALL FUNCTION

1.

Turn ignition switch ON.

2.

Pinch fuel feed hose with two fingers.
Fuel pressure pulsation should be felt on the fuel feed hose
for 5 second after ignition switch is turned ON.

OK or NG

OK

>> INSPECTION END

NG

>> GO TO 2.

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

38

G/R

Fuel pump control module 
(FPCM) check

[When cranking engine]

Approximately 0V

[Engine is running]

●

Warm-up condition

●

Idle speed

4 - 6V

39

B/R

Fuel pump control module
(FPCM)

[When cranking engine]

0 - 0.5V

[Engine is running]

●

Warm-up condition

●

Idle speed

8 - 12V

113

GY

Fuel pump relay

[Ignition switch: ON]

●

For 5 seconds after turning ignition switch 
ON

[Engine is running]

0 - 1.5V

[Ignition switch: ON]

●

More than 5 seconds after turning ignition 
switch ON

BATTERY VOLTAGE
(11 - 14V)

PBIB2440E

EC-718

FUEL PUMP

2. 

CHECK FUEL PUMP RELAY POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect fuel pump relay.

3.

Turn ignition switch ON.

4.

Check voltage between fuel pump relay terminals 2, 3 and
ground with CONSULT-II or tester.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 3.

3. 

DETECT MALFUNCTIONING PART

Check the following.

●

Fuse block (J/B) No. 1 connector M1

●

Fuse block (J/B) No. 2 connectors M143, M145

●

15A fuses

●

Harness for open or short between fuse and fuel pump relay

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

PBIB0040E

Voltage: Battery voltage

PBIB0185E