Nissan Pathfinder (2009 year). Manual — part 325

EC-614

< COMPONENT DIAGNOSIS >

[VK56DE]

P0125 ECT SENSOR

If “COOLAN TEMP/S” indication increases to more than 31

°

C (88

°

F) within 65 minutes, stop engine

because the test result will be OK.

5.

Check 1st trip DTC.

6.

If 1st trip DTC is detected, go to

EC-614, "Diagnosis Procedure"

.

WITH GST

Follow the procedure “WITH CONSULT-III” above.

Diagnosis Procedure

INFOID:0000000003936541

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten ground screws on the body.
Refer to

EC-568, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to

EC-614, "Component Inspection"

.

OK or NG

OK

>> GO TO 3.

NG

>> Replace engine coolant temperature sensor.

3.

CHECK THERMOSTAT OPERATION

When the engine is cold [lower than 70

°

C (158

°

F)] condition, grasp lower radiator hose and check that the

engine coolant does not flow.

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace thermostat. Refer to

CO-54, "Removal and Installation"

.

4.

CHECK INTERMITTENT INCIDENT

Refer to

GI-49, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004333348

ENGINE COOLANT TEMPERATURE SENSOR

BBIA0539E

2009 Pathfinder

P0125 ECT SENSOR

EC-615

< COMPONENT DIAGNOSIS >

[VK56DE]

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1.

Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.

2.

If NG, replace engine coolant temperature sensor.

PBIB2005E

Engine coolant temperature [

°

C (

°

F)]

Resistance (k

Ω

)

20 (68)

2.1 - 2.9

50 (122)

0.68 - 1.00

90 (194)

0.236 - 0.260

SEF012P

2009 Pathfinder

EC-616

< COMPONENT DIAGNOSIS >

[VK56DE]

P0127 IAT SENSOR

P0127 IAT SENSOR

Component Description

INFOID:0000000004333339

The intake air temperature sensor is built-into the mass air flow sen-
sor. The sensor detects intake air temperature and transmits a signal
to the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the rise in temperature.

<Reference data>

*: This data is reference value and is measured between ECM terminal 34 (Intake air
temperature sensor) and ground.

CAUTION:

Never use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.

On Board Diagnosis Logic

INFOID:0000000003936544

DTC Confirmation Procedure

INFOID:0000000003936545

NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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.

CAUTION:

Always drive vehicle at a safe speed.
TESTING CONDITION:
This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road
test is expected to be easier, it is unnecessary to lift the vehicle.

WITH CONSULT-III

1.

Wait until engine coolant temperature is less than 90

°

C (194

°

F)

a.

Turn ignition switch ON.

b.

Select “DATA MONITOR” mode with CONSULT-III.

c.

Check the engine coolant temperature.

BBIA0355E

Intake air temperature

[

°

C (

°

F)]

Voltage* (V)

Resistance (k

Ω

)

25 (77)

3.3

1.800 - 2.200

80 (176)

1.2

0.283 - 0.359

SEF012P

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0127
0127

Intake air temperature
too high

Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signal
from engine coolant temperature sensor.

• Harness or connectors

(The sensor circuit is open or shorted)

• Intake air temperature sensor

2009 Pathfinder

P0127 IAT SENSOR

EC-617

< COMPONENT DIAGNOSIS >

[VK56DE]

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d.

If the engine coolant temperature is not less than 90

°

C (194

°

F), turn ignition switch OFF and cool down

engine.
• Perform the following steps before engine coolant temperature is above 90

°

C (194

°

F).

2.

Turn ignition switch ON.

3.

Select “DATA MONITOR” mode with CONSULT-III.

4.

Start engine.

5.

Hold vehicle speed at more than 70 km/h (43 MPH) for 100 consecutive seconds.

6.

Check 1st trip DTC.

7.

If 1st trip DTC is detected, go to

EC-617, "Diagnosis Procedure"

.

WITH GST

Follow the procedure “WITH CONSULT-III” above.

Diagnosis Procedure

INFOID:0000000003936546

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten ground screws on the body.
Refer to

EC-568, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK INTAKE AIR TEMPERATURE SENSOR

Refer to

EC-617, "Component Inspection"

.

OK or NG

OK

>> GO TO 3.

NG

>> Replace mass air flow sensor (with intake air temperature sensor).

3.

CHECK INTERMITTENT INCIDENT

Refer to

GI-49, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004333350

INTAKE AIR TEMPERATURE SENSOR

BBIA0539E

2009 Pathfinder

EC-618

< COMPONENT DIAGNOSIS >

[VK56DE]

P0127 IAT SENSOR

1.

Check resistance between intake air temperature sensor termi-
nals 5 and 6 under the following conditions.

2.

If NG, replace mass air flow sensor (with intake air temperature
sensor).

Intake air temperature [

°

C (

°

F)]

Resistance (k

Ω

)

25 (77)

1.800 - 2.200

BBIA0355E

SEF012P

2009 Pathfinder

P0128 THERMOSTAT FUNCTION

EC-619

< COMPONENT DIAGNOSIS >

[VK56DE]

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P0128 THERMOSTAT FUNCTION

On Board Diagnosis Logic

INFOID:0000000003936548

NOTE:
If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307 or P0308,
first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307,
P0308. Refer to

EC-677, "DTC Confirmation Procedure"

.

Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leakage in the seal or the thermostat being stuck open.

DTC Confirmation Procedure

INFOID:0000000003936549

NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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.

WITH CONSULT-III

TESTING CONDITION:
• For best results, perform at ambient temperature of –10

°

C (14

°

F) or higher.

• For best results, perform at engine coolant temperature of –10

°

C (14

°

F) to 56

°

C (133

°

F).

• Before performing the following procedure, do not add fuel.

1.

Turn A/C switch OFF.

2.

Turn blower fan switch OFF.

3.

Turn ignition switch ON.

4.

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

5.

Check the indication of “COOLAN TEMP/S”.
If it is below 56

°

C (133

°

F), go to next step.

If it is above 56

°

C (133

°

F), cool down the engine to less than 56

°

C (133

°

F). Then go to next steps.

6.

Start engine and drive vehicle for 10 consecutive minutes under the following conditions.

If “COOLAN TEMP/S” increases to more than 75

°

C (167

°

F) within 10 minutes, turn ignition switch

OFF because the test result will be OK.

7.

Check 1st trip DTC.

8.

If 1st trip DTC is detected, go to

EC-619, "Diagnosis Procedure"

.

WITH GST

Follow the procedure “WITH CONSULT-III” above.

Diagnosis Procedure

INFOID:0000000003936550

1.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to

EC-620, "Component Inspection"

.

OK or NG

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0128
0128

Thermostat function

The engine coolant temperature does not
reach to specified temperature even though
the engine has run long enough.

• Thermostat
• Leakage from sealing portion of thermostat
• Engine coolant temperature sensor

VHCL SPEED SE

More than 56 km/h (35 MP)

2009 Pathfinder

EC-620

< COMPONENT DIAGNOSIS >

[VK56DE]

P0128 THERMOSTAT FUNCTION

OK

>> GO TO 2.

NG

>> Replace engine coolant temperature sensor.

2.

CHECK THERMOSTAT

Refer to

CO-54, "Removal and Installation"

.

OK or NG

OK

>> INSPECTION END

NG

>> Replace thermostat.

Component Inspection

INFOID:0000000004354979

ENGINE COOLANT TEMPERATURE SENSOR

1.

Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.

2.

If NG, replace engine coolant temperature sensor.

PBIB2005E

Engine coolant temperature [

°

C (

°

F)]

Resistance (k

Ω

)

20 (68)

2.1 - 2.9

50 (122)

0.68 - 1.00

90 (194)

0.236 - 0.260

SEF012P

2009 Pathfinder

P0130, P0150 A/F SENSOR 1

EC-621

< COMPONENT DIAGNOSIS >

[VK56DE]

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P0130, P0150 A/F SENSOR 1

Component Description

INFOID:0000000003936552

The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is composed an elec-
trode layer, which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of approxi-
mately 800

°

C (1,472

°

F).

On Board Diagnosis Logic

INFOID:0000000003936553

To judge malfunctions, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1 sig-
nal fluctuates according to fuel feedback control.

DTC Confirmation Procedure

INFOID:0000000003936554

Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
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.

TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.

PROCEDURE FOR MALFUNCTION A

1.

Start engine and warm it up to normal operating temperature.

2.

Let engine idle for 2 minutes.

3.

Check 1st trip DTC.

4.

If 1st trip DTC is detected, go to

EC-622, "Diagnosis Procedure"

.

PROCEDURE FOR MALFUNCTION B

PBIB3353E

PBIB3354E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0130
0130
(Bank 1)

Air fuel ratio (A/F) sensor 1
circuit

A)

The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly in a range other
than approx. 2.2V.

• Harness or connectors

(The A/F sensor 1 circuit is open
or shorted.)

• Air fuel ratio (A/F) sensor 1

P0150
0150
(Bank 2)

B)

The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 2.2V.

2009 Pathfinder