Nissan Cube. Manual - part 322

EC-174

< DTC/CIRCUIT DIAGNOSIS >

[MR18DE]

P0125 ECT SENSOR

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace engine coolant temperature sensor. Refer to 

CO-23, "Exploded View"

.

Terminals

Condition

Resistance

1 and 2

Temperature [

°

C (

°

F)]

20 (68)

2.37 - 2.63 k

Ω

50 (122)

0.68 - 1.00 k

Ω

90 (194)

0.236 - 0.260 k

Ω

P0127 IAT SENSOR

EC-175

< DTC/CIRCUIT DIAGNOSIS >

[MR18DE]

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P0127 IAT SENSOR

Description

INFOID:0000000009947299

The intake air temperature sensor is built-into mass air flow sensor
(1). 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 temperature rise.

<Reference data>

*: These data are reference values and are measured between ECM terminal 46
(Intake air temperature sensor) and ground.

DTC Logic

INFOID:0000000009947300

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

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

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT

1.

Wait until engine coolant temperature is less than 96

°

C (205

°

F)

-

Turn ignition switch ON.

-

Select “DATA MONITOR” mode with CONSULT.

-

Check the engine coolant temperature.

-

If the engine coolant temperature is not less than 96

°

C (205

°

F), turn ignition switch OFF and cool down

engine.

NOTE:
Perform the following steps before engine coolant temperature is above 96

°

C (205

°

F).

PBIA9559J

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

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

EC-176

< DTC/CIRCUIT DIAGNOSIS >

[MR18DE]

P0127 IAT SENSOR

2.

Turn ignition switch ON.

3.

Select “DATA MONITOR” mode with CONSULT.

4.

Start engine.

5.

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

CAUTION:

Always drive vehicle at a safe speed.

6.

Check 1st trip DTC.

With GST

Follow the procedure “With CONSULT” above.

Is 1st trip DTC detected?

YES

>> Go to 

EC-176, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009947301

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection E38. Refer to 

GI-43, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK INTAKE AIR TEMPERATURE SENSOR

Refer to 

EC-176, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

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

EM-24, "Exploded

View"

.

3.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000009947302

1.

CHECK INTAKE AIR TEMPERATURE SENSOR

1.

Turn ignition switch OFF.

2.

Disconnect mass air flow sensor harness connector.

3.

Check resistance between mass air flow sensor terminals as per the following.

Is the inspection result normal?

YES

>> INSPECTION END

NO

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

EM-24, "Exploded

View"

.

Terminals

Condition

Resistance (k

Ω

)

1 and 2

Intake air temperature [

°

C (

°

F)]

25 (77)

1.800 - 2.200

P0128 THERMOSTAT FUNCTION

EC-177

< DTC/CIRCUIT DIAGNOSIS >

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P0128 THERMOSTAT FUNCTION

DTC Logic

INFOID:0000000009947303

DTC DETECTION LOGIC

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

EC-233, "DTC Logic"

.

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

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC CONFIRMATION PROCEDURE has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.
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 52

°

C (126

°

F).

• Before performing the following procedure, do not fill with the fuel.

>> GO TO 2.

2.

PRECONDITIONING-II

With CONSULT

1.

Turn ignition switch ON.

2.

Check the following conditions:

3.

Select “DATA MONITOR” mode of “ENGINE” using CONSULT.

4.

Check the following conditions:

Is the condition satisfied?

YES

>> GO TO 3.

NO

>> 1.

Satisfy the condition.

2.

GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE-I

With CONSULT

1.

Start engine.

2.

Drive the vehicle until the following condition is satisfied.

CAUTION:

Always drive vehicle at safe speed.

-

STEP 1

Drive the vehicle under the conditions instructed below until the difference between “COOLAN TEMP/S” and

“FUEL T/TMP SE” becomes at least 24

°

C (43

°

F).

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0128

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

Ambient temperature

−

10

°

C (14

°

F) or more

A/C switch

OFF

Blower fan switch

OFF

COOLAN TEMP/S

−

10

°

C – 52

°

C (14 – 126

°

F)