Nissan Altima L32. Manual - part 397

P0116 ECT SENSOR

EC-709

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

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EC

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P0116 ECT SENSOR

Description

INFOID:0000000004349674

The engine coolant temperature sensor is used to detect the engine

coolant temperature. The sensor modifies a voltage signal from the

ECM. The modified signal returns to the ECM as the engine coolant

temperature input. The sensor uses a thermistor which is sensitive to

the change in temperature. The electrical resistance of the ther-

mistor decreases as temperature increases.

<Reference data>

*: These data are reference values and are measured between ECM terminals 46
(Engine coolant temperature sensor) and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transis-
tor. Use a ground other than ECM terminals, such as the ground.

DTC Logic

INFOID:0000000004349675

DTC DETECTION LOGIC

NOTE:

If DTC P0116 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117,

P0118. Refer to 

EC-711, "DTC 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.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine and warm it up to normal operating temperature.

2. Rev engine up to 2,000 rpm for more than 10 minutes.

3. Move the vehicle to a cool place, then stop engine and turn ignition switch OFF.

4. Check resistance between “fuel level sensor unit and fuel pump” terminals 4 and 5.

SEF594K

Engine coolant temperature

[

°C (°F)]

Voltage* (V)

Resistance (k

Ω)

–10 (14)

4.4

7.0 - 11.4

20 (68)

3.5

2.37 - 2.63

50 (122)

2.2

0.68 - 1.00

90 (194)

0.9

0.236 - 0.260

SEF012P

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0116

Engine coolant tempera-
ture sensor circuit range/
performance

Engine coolant temperature signal from engine 
coolant temperature sensor does not fluctuate, 
even when some time has passed after starting 
the engine with pre-warming up condition.

• Harness or connectors

(High or low resistance in the circuit)

• Engine coolant temperature sensor

EC-710

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

P0116 ECT SENSOR

5. Soak the vehicle until the resistance between “fuel level sensor unit and fuel pump” terminals 4 and 5

becomes 0.5 k

Ω higher than the value measured before soaking.

CAUTION:

Never turn ignition switch ON during the soaking time.

NOTE:

Soak time changes depending on ambient air temperature. It may take several hours.

6. Start engine and let it idle for 5 minutes.

7. Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>>

EC-710, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000004349676

1.

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

2. Check ground connection E9. Refer to GROUND INSPECTION in 

GI-45, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EC-710, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Replace engine coolant temperature sensor.

3.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004349677

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.

4. Check resistance between engine coolant temperature sensor

terminals as follows.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace engine coolant temperature sensor.

Terminals

Condition

Resistance (k

Ω)

1 and 2

Temperature [

°C (°F)]

20 (68)

2.37 - 2.63

50 (122)

0.68 - 1.00

90 (194)

0.236 - 0.260

PBIB2005E

P0117, P0118 ECT SENSOR

EC-711

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

P0117, P0118 ECT SENSOR

Description

INFOID:0000000004349678

The engine coolant temperature sensor is used to detect the engine

coolant temperature. The sensor modifies a voltage signal from the

ECM. The modified signal returns to the ECM as the engine coolant

temperature input. The sensor uses a thermistor which is sensitive to

the change in temperature. The electrical resistance of the ther-

mistor decreases as temperature increases.

<Reference data>

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

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transis-
tor. Use a ground other than ECM terminals, such as the ground.

DTC Logic

INFOID:0000000004349679

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.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1. Turn ignition switch ON and wait at least 5 seconds.

2. Check DTC.
Is DTC detected?

YES

>> Go to 

EC-712, "Diagnosis Procedure"

.

NO

>> INSPECTION END

SEF594K

Engine coolant temperature

°C (°F)

Voltage* V

Resistance k

Ω

–10 (14)

4.4

7.0 - 11.4

20 (68)

3.5

2.37 - 2.63

50 (122)

2.2

0.68 - 1.00

90 (194)

0.9

0.236 - 0.260

SEF012P

DTC No.

Trouble Diagnosis 

Name

DTC detecting condition

Possible Cause

P0117

Engine coolant tem-
perature sensor cir-
cuit low input

An excessively low voltage from the sensor is 
sent to ECM.

• Harness or connectors

(The sensor circuit is open or shorted.)

• Engine coolant temperature sensor 

P0118

Engine coolant tem-
perature sensor cir-
cuit high input

An excessively high voltage from the sensor is 
sent to ECM.

EC-712

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

P0117, P0118 ECT SENSOR

Diagnosis Procedure

INFOID:0000000004349680

1.

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

2. Check ground connection E9. Refer to Ground Inspection in 

GI-45, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK ECT SENSOR POWER SUPPLY CIRCUIT

1. Disconnect engine coolant temperature (ECT) sensor harness connector.

2. Turn ignition switch ON.

3. Check the voltage between ECT sensor harness connector and

ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair open circuit or short to ground or short to power

in harness or connectors.

3.

CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the continuity between ECT sensor harness connector and ECM harness connector.

4. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 4.

NO

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

4.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EC-712, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace engine coolant temperature sensor.

5.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004349681

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.

ECT sensor

Ground

Voltage

Connector

Terminal

F11

1

Ground

Approx. 5V

PBIB0080E

ECT sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

F11

2

F13

52

Existed