Infiniti M45 (Y34). Manual - part 497

FUEL PUMP CIRCUIT

EC-677

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3. 

DETECT MALFUNCTIONING PART

Check the following.

●

Fuse block (J/B) No. 1 connector M1

●

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

●

Joint connector-19

●

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.

4. 

CHECK FUEL PUMP POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect “fuel level sensor unit and fuel pump” harness con-
nector.

3.

Disconnect dropping resistor harness connector.

4.

Check harness continuity between 
fuel pump relay terminal 5 and “fuel level sensor unit and fuel pump” terminal 3, 
“fuel level sensor unit and fuel pump” terminal 1 and dropping resistor terminal 2,
dropping resistor terminal 1 and ground.
Refer to Wiring Diagram.

5.

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

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

PBIB1127E

Continuity should exist.

PBIB1129E

EC-678

FUEL PUMP CIRCUIT

5. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors B211, M141

●

Harness connectors B62, B262

●

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

●

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

●

Harness for open or short between  “fuel level sensor unit and fuel pump” and dropping resistor

●

Harness for open or short between dropping resistor and ground

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

6. 

CHECK FUEL PUMP RELAY OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Disconnect ECM harness connector.

2.

Check harness continuity between ECM terminal 41 and fuel pump relay terminal 1.
Refer to Wiring Diagram.

3.

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

OK or NG

OK

>> GO TO 8.

NG

>> GO TO 7.

7. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M135, F105

●

Harness for open or short between ECM and fuel pump relay

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

8. 

CHECK DROPPING RESISTOR

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

OK or NG

OK

>> GO TO 9.

NG

>> Replace dropping resistor.

9. 

CHECK FUEL PUMP RELAY

Refer to 

EC-679, "Component Inspection"

 .

OK or NG

OK

>> GO TO 10.

NG

>> Replace fuel pump relay.

10. 

CHECK FUEL PUMP

Refer to 

EC-679, "Component Inspection"

 .

OK or NG

OK

>> GO TO 11.

NG

>> Replace fuel pump.

Continuity should exist.

FUEL PUMP CIRCUIT

EC-679

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11. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Component Inspection

ABS002U3

FUEL PUMP RELAY

Check continuity between fuel pump relay terminals 3 and 5 under
the following conditions.

FUEL PUMP

1.

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

2.

Check resistance between “fuel level sensor unit and fuel pump”
terminals 1 and 3.

DROPPING RESISTOR

Check resistance between dropping resistor terminals 1 and 2.

Removal and Installation

ABS002U4

FUEL PUMP

Refer to 

FL-3, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY"

 .

Conditions

Continuity

12V direct current supply 
between terminals 1 and 2

Yes

No current supply

No

PBIB0098E

Resistance: 0.2 - 5.0

Ω

 [at 25

°

C (77

°

F)]

PBIB0186E

Resistance: Approximately 0.9

Ω

 [at 20

°

C (68

°

F)]

PBIB0100E

EC-680

REFRIGERANT PRESSURE SENSOR

REFRIGERANT PRESSURE SENSOR

PFP:92136

Component Description

ABS002U5

The refrigerant pressure sensor is installed at the condenser of the
air conditioner system. The sensor uses an electrostatic volume
pressure transducer to convert refrigerant pressure to voltage. The
voltage signal is sent to ECM, and ECM controls cooling fan system.

PBIB1113E

PBIB2657E