Infiniti QX56 (Z62). Manual — part 573

EC-270

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

2.

Listen to each fuel injector operating sound.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Perform trouble diagnosis for fuel injector, refer to

EC-

498, "Diagnosis Procedure"

.

7.

CHECK INTERMITTENT INCIDENT

Refer to

GI-40, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace fuel injector. Refer to

EM-49, "Removal and Installation"

.

NO

>> Repair or replace malfunctioning part.

Clicking sound should be heard.

PBIB3332E

P0181 FTT SENSOR

EC-271

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

C

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EC

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P0181 FTT SENSOR

DTC Logic

INFOID:0000000006288289

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

1.

Turn ignition switch OFF and wait at least 10 seconds.

2.

Turn ignition switch ON.

3.

Turn ignition switch OFF and wait at least 10 seconds.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE-I

1.

Turn ignition switch ON and wait at least 10 seconds.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Proceed to

EC-271, "Diagnosis Procedure"

.

NO

>> GO TO 3.

3.

CHECK ENGINE COOLANT TEMPERATURE

WITH CONSULT-III

1.

Select “COOLAN TEMP/S” in “DATA MONITOR” with CONSULT-III.

2.

Check “COOLAN TEMP/S” value.

WITH GST

Follow the procedure “With CONSULT-III” above.

“COOLAN TEMP/S” less than 60

°

C (140

°

F)?

YES

>> INSPECTION END

NO

>> GO TO 4.

4.

PERFORM DTC CONFIRMATION PROCEDURE-II

WITH CONSULT-III

1.

Cool engine down until “COOLAN TEMP/S” is less than 60

°

C (140

°

F).

2.

Wait at least 10 seconds.

3.

Check 1st trip DTC.

WITH GST

Follow the procedure “With CONSULT-III” above.

Is 1st trip DTC detected?

YES

>> Proceed to

EC-271, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006288290

1.

CHECK DTC WITH COMBINATION METER

Refer to

MWI-30, "CONSULT-III Function"

.

Is the inspection result normal?

YES

>> GO TO 2.

DTC No.

Trouble diagnosis name

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P0181

FTT SENSOR
[Fuel tank temperature sensor
circuit range/performance]

Rationally incorrect voltage from the sensor
is sent to ECM, compared with the voltage
signals from engine coolant temperature sen-
sor and intake air temperature sensor.

• Harness or connectors

(The FTT sensor circuit is open or
shorted)

• Fuel tank temperature sensor
• Combination meter

EC-272

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

P0181 FTT SENSOR

NO

>> Proceed to

MWI-69, "Component Function Check"

.

2.

CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT

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 4.

NO

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.
• Harness for open or short between ECM and “fuel level sensor unit and fuel pump”
• Loose or poor connection for each connector and harness

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

4.

CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect “combination meter” harness connector.

3.

Check the continuity between “fuel level sensor unit and fuel pump” harness connector and “combination
meter” harness connector.

4.

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

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following.
• Harness for open or short between “fuel level sensor unit and fuel pump” and “combination meter”
• Loose or poor connection for each connector and harness

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

6.

CHECK FUEL TANK TEMPERATURE SENSOR

Refer to

EC-273, "Component Inspection (Fuel Tank Temperature Sensor)"

.

Is the inspection result normal?

YES

>> GO TO 7.

NO

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

FL-5, "Removal and Installation"

.

7.

CHECK INTERMITTENT INCIDENT

Refer to

GI-40, "Intermittent Incident"

.

>> INSPECTION END

Fuel level sensor unit and

fuel pump

Ground

Voltage (V)

Connector

Terminal

C5

4

Ground

Approx. 5

Fuel level sensor unit and

fuel pump

Combination meter

Continuity

Connector

Terminal

Connector

Terminal

C5

5

M34

24

Existed

P0181 FTT SENSOR

EC-273

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

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Component Inspection (Fuel Tank Temperature Sensor)

INFOID:0000000006288291

1.

CHECK FUEL TANK TEMPERATURE SENSOR

1.

Turn ignition switch OFF.

2.

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

3.

Remove fuel level sensor unit.

4.

Check resistance between “fuel level sensor unit and fuel pump
” terminals by heating with hot water as shown in the figure.

Is the inspection result normal?

YES

>> INSPECTION END

NO

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

Terminals

Condition

Resistance (k

Ω

)

4 and 5

Temperature [

°

C (

°

F)]

20 (68)

2.3 - 2.7

50 (122)

0.79 - 0.90

JMBIA0167ZZ