Nissan Quest E52. Manual - part 497

EC-198

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0122, P0123 TP SENSOR

4.

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

Is the inspection result normal?

YES

>> GO TO 3.

NO

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

3.

CHECK THROTTLE POSITION SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check the continuity between electric throttle control actuator harness connector and ECM harness con-
nector.

2.

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

Is the inspection result normal?

YES

>> GO TO 4.

NO

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

4.

CHECK THROTTLE POSITION SENSOR

Check throttle position sensor. Refer to 

EC-198, "Component Inspection"

.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-42, "Intermittent Incident"

.

NO

>> Replace electric throttle control actuator. Refer to 

EM-28, "Exploded View"

.

Component Inspection

INFOID:0000000009651056

1.

CHECK THROTTLE POSITION SENSOR

1.

Turn ignition switch OFF.

2.

Reconnect all harness connectors disconnected.

3.

Perform 

EC-136, "Work Procedure"

.

4.

Turn ignition switch ON.

5.

Set selector lever to D position.

6.

Check the voltage between ECM harness connector terminals under the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace electric throttle control actuator. Refer to 

EM-28, "Exploded View"

.

Electric throttle control actuator

ECM

Continuity

Connector

Terminal

Connector

Terminal

F29

4

F7

19

Existed

Electric throttle control actuator

ECM

Continuity

Connector

Terminal

Connector

Terminal

F29

3

F7

23

Existed

ECM

Condition

Voltage

Connector

+

–

Terminal

Terminal

F7

22

(TP sensor 1 sig-

nal)

19

(Sensor ground)

Accelerator pedal

Fully released

More than 0.36 V

Fully depressed

Less than 4.75 V

23

(TP sensor 2 sig-

nal)

Fully released

Less than 4.75 V

Fully depressed

More than 0.36 V

P0125 ECT SENSOR

EC-199

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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P0125 ECT SENSOR

DTC Logic

INFOID:0000000009651057

DTC DETECTION LOGIC

NOTE:
• If DTC P0125 is displayed with P0116, first perform the trouble diagnosis for DTC P0116. Refer to 

EC-

193, "DTC Logic"

.

• If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117,

P0118. Refer to 

EC-195, "DTC Logic"

.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next test.
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.

CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION

With CONSULT

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT.

3.

Check that “COOLAN TEMP/S” is above 10

°

C (50

°

F).

With GST

Follow the procedure “With CONSULT” above.

Is the temperature above 10

°

C (50

°

F)?

YES

>> INSPECTION END

NO

>> GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT

1.

Start engine and run it for 65 minutes at idle speed.
If “COOLAN TEMP/S” increases to more than 10

°

C (50

°

F) within 65 minutes, stop engine because

the test result will be OK.

CAUTION:

Never overheat engine.

2.

Check 1st trip DTC.

With GST

Follow the procedure “With CONSULT” above.

Is 1st trip DTC detected?

YES

>>

EC-199, "Diagnosis Procedure"

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009651058

1.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Check engine coolant temperature sensor. Refer to 

EC-200, "Component Inspection"

.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0125

Insufficient engine cool-
ant temperature for 
closed loop fuel control

• Voltage sent to ECM from the sensor is not 

practical, even when some time has passed 
after starting the engine.

• Engine coolant temperature is insufficient for 

closed loop fuel control.

• Harness or connectors

(High resistance in the circuit)

• Engine coolant temperature sensor
• Thermostat

EC-200

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0125 ECT SENSOR

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace engine coolant temperature sensor.

2.

CHECK THERMOSTAT OPERATION

When the engine is cold [lower than 70

°

C (158

°

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

engine coolant does not flow.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-42, "Intermittent Incident"

.

NO

>> Repair or replace thermostat. Refer to 

CO-24, "Exploded View"

.

Component Inspection

INFOID:0000000009651059

1.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

1.

Turn ignition switch OFF.

2.

Disconnect engine coolant temperature sensor harness connector.

3.

Remove engine coolant temperature sensor. Refer to 

CO-26, "Exploded View"

.

4.

Check resistance between engine coolant temperature sensor
terminals as per the following.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace engine coolant temperature sensor. Refer to

CO-26, "Exploded View"

.

Terminals

Condition

Resistance (k

Ω

)

1 and 2

Temperature [

°

C (

°

F)]

20 (68)

2.1 - 2.9

50 (122)

0.68 - 1.00

90 (194)

0.236 - 0.260

JMBIA0080ZZ

P0127 IAT SENSOR

EC-201

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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P0127 IAT SENSOR

DTC Logic

INFOID:0000000009651060

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next test.
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:
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).

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

>> Proceed to 

EC-201, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009651061

1.

CHECK INTAKE AIR TEMPERATURE SENSOR

Check intake air temperature sensor. Refer to 

EC-202, "Component Inspection"

.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-42, "Intermittent Incident"

.

NO

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

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