Infiniti M45 (Y34). Manual - part 472

DTC P1464 FUEL LEVEL SENSOR

EC-577

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Removal and Installation

ABS002R6

FUEL LEVEL SENSOR

Refer to 

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

 .

EC-578

DTC P1480 COOLING FAN SPEED CONTROL SOLENOID VALVE

DTC P1480 COOLING FAN SPEED CONTROL SOLENOID VALVE

PFP:21010

Description

ABS002R7

SYSTEM DESCRIPTION

This system controls the cooling fan operating speed. The opening of the cooling fan speed control solenoid
valve changes to control oil pressure provided to the cooling fan drive pump.
This system consists of the cooling fan pump, cooling fan drive pump, cooling fan speed control solenoid
valve, oil cooler, cooling fan fluid reservoir, etc.
The cooling fan pump is operated by engine with the drive belts and provides oil pressure to the cooling fan
drive pump which operates the cooling fan. The cooling fan speed control solenoid valve is installed between
the cooling fan pump and cooling fan drive pump. The solenoid valve repeats ON/OFF operation according to
the signal sent from the ECM. The opening of the solenoid valve varies for optimum engine control. The opti-
mum value stored in the ECM is determined by considering various engine conditions.

COOLING FAN SPEED CONTROL

*: This signal is sent to the ECM through CAN communication line.

The ECM controls the cooling fan speed corresponding to the engine speed, the radiator coolant temperature,
refrigerant pressure, vehicle speed, air conditioner switch signal, etc.
The ECM determines the target fan speed based on the basic fan speed considering the radiator coolant tem-
perature and the engine speed. The ECM controls fan speed between 0 to 2,550 rpm.
When the cooling fan speed control solenoid valve is malfunctioning (does not operate), the cooling fan is
operated at the maximum speed by engine through the drive belts.

Cooling Fan Basic Speed

unit: rpm

PBIB0116E

Sensor

Input signal to ECM

ECM function

Actuator

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

Engine speed

Cooling fan speed control

Cooling fan speed control 
solenoid valve

Accelerator pedal position sensor

Accelerator pedal position

Radiator coolant temperature sensor

Radiator coolant temperature

Refrigerant pressure sensor

Refrigerant pressure

Wheel sensors*

Vehicle speed

A/C auto amp.*

Air conditioner switch signal

Air condi-

tioner

Refrigerant pressure

Vehicle speed

Less than 20 km/h 

(12 MPH)

20 - 80 km/h

(12 - 50 MPH)

More than 80 km/h 

(50 MPH)

OFF

-

300

300

300

ON

Less than 680 kPa (6.94 kg/cm

2

 , 98.6 psi)

700

400

300

680 - 1,660 kPa (6.94 - 16.93 kg/cm

2

 , 98.6 - 240.7 psi)

900

700

300

1,660 - 1,960 kPa (16.93 - 19.99 kg/cm

2

 , 240.7 - 284.2 

psi)

1100

1100

1250

More than 1,960 kPa (19.99 kg/cm

2

 , 284.2 psi)

1250

1200

1250

DTC P1480 COOLING FAN SPEED CONTROL SOLENOID VALVE

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COMPONENT DESCRIPTION
Cooling Fan Speed Control Solenoid Valve

The cooling fan speed control solenoid valve uses a ON/OFF duty to control the pressure of the cooling fan
fluid from the cooling fan pump. This solenoid valve is moved by ON/OFF pulse from the ECM. The longer the
ON pulse is sent to the solenoid valve, the lower speed the cooling fan operates.

CONSULT-II Reference Value in Data Monitor Mode

ABS002R8

Specification data are reference values.

On Board Diagnosis Logic

ABS002R9

This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.

DTC Confirmation Procedure

ABS002RB

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

PROCEDURE FOR MALFUNCTION A

 With CONSULT-II

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Confirm “RADIATOR TEMP” indicates less than 80 

°

C (176 

°

F).

If not, cool down the engine.

4.

Start engine and let it idle for at least 5 seconds.

5.

If DTC is detected, go to 

EC-582, "Diagnostic Procedure"

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 With GST

1.

Turn ignition switch ON.

2.

Set voltmeter probes between ECM terminal 122 (radiator coolant temperature sensor signal) and
ground.

3.

Check the voltage should be above 1.23V.
If not, cool down the engine.

4.

Start engine and let it idle for at least 5 seconds.

5.

If DTC is detected, go to 

EC-582, "Diagnostic Procedure"

 .

MONITOR ITEM

CONDITION

SPECIFICATION

TRGT FAN RPM

●

Ignition switch: ON (Engine stopped)

0 rpm

●

Engine: Idle

300 - 2,550 rpm

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1480
1480

Cooling fan speed control 
solenoid valve circuit

A)

An excessively low ampere of current flows 
through the cooling fan speed control solenoid 
valve to ECM, even though the radiator coolant 
temperature is low,

●

Harness or connectors
(Cooling fan speed control 
solenoid valve circuit is open 
or shorted.)

●

Cooling fan speed control 
solenoid valve

B)

An excessively high ampere of current flows 
through the cooling fan speed control solenoid 
valve to ECM, even though the radiator coolant 
temperature is high.

PBIB1863E

EC-580

DTC P1480 COOLING FAN SPEED CONTROL SOLENOID VALVE

PROCEDURE FOR MALFUNCTION B

 With CONSULT-II

1.

Turn ignition switch OFF.

2.

Disconnect radiator coolant temperature sensor harness connector.

3.

Connect 2.2 k

Ω

 resistor to the radiator coolant temperature sensor harness connector.

4.

Turn ignition switch ON.

5.

Select “DATA MONITOR” mode with CONSULT-II.

6.

Start engine and let it idle for at least 5 seconds.

7.

If DTC is detected, go to 

EC-582, "Diagnostic Procedure"

 .

 With GST

Follow the procedure With CONSULT-II above.

PBIB1863E