Nissan Pathfinder (2012 year). Manual - part 256

P0116 ECT SENSOR

EC-129

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

P0116 ECT SENSOR

Component Description

INFOID:0000000007358036

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>

*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and 67 (Sensor ground).

CAUTION:

Never use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-

age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

On Board Diagnosis Logic

INFOID:0000000007358037

DTC Confirmation Procedure

INFOID:0000000007358038

1.

INSPECTION START

Is it necessary to erase permanent DTC?

YES

>> GO TO 3.

NO

>> GO TO 2.

2.

PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to 

EC-130, "Component Function Check"

.

NOTE:

Use the component function check to check the overall function of the ECT sensor circut. During this check, a

1st trip DTC might not be confirmed.
Is the inspection result normal?

SEF594K

Engine coolant 

temperature

°

C (

°

F)]

Voltage* (V)

Resistance (k

Ω

)

−

10 (14)

4.4

7.0 - 11.4

20 (68)

3.5

2.1 - 2.9

50 (122)

2.2

0.68 - 1.00

90 (194)

0.9

0.236 - 0.260

SEF012P

DTC No.

Trouble diagnosis

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P0116

ECT SEN/CIRC
[Engine coolant temperature 
(ECT) sensor circuit range/per-
formance]

The comparison result of signals transmitted 
to ECM from each temperature sensor (IAT 
sensor, ECT sensor, and FTT sensor) shows 
that the voltage signal of the ECT sensor is 
higher/lower than that of other temperature 
sensors when the engine is started with its 
cold state.

• Harness or connectors

(High or low resistance in the ECT 
sensor circuit)

• ECT sensor

August 2012

2012 Pathfinder

EC-130

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

P0116 ECT SENSOR

YES

>> INSPECTION END

NO

>> Proceed to 

EC-131, "Diagnosis Procedure"

.

3.

PRECONDITIONING

If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following proce-

dure before conducting 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:

•

Before performing the following procedure, do not add fuel.

•

Before performing the following procedure, check that fuel level is between 1/4 and 4/4.

•

Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.

>> GO TO 4.

4.

PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine and let it idle for 60 minutes.

2. Move the vehicle to a cool place.

NOTE:

Cool the vehicle in an environment of ambient air temperature between 

−

10

°

C (14

°

F) and 35

°

C (95

°

F).

3. Turn ignition switch OFF and soak the vehicle for 12 hours.

CAUTION:

Never turn ignition switch ON during soaking.

NOTE:

The vehicle must be cooled with the food open.

4. Start engine and let it idle for 5 minutes or more.

CAUTION:

Never turn ignition switch OFF during idling.

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

YES

>> Proceed to 

EC-131, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Component Function Check

INFOID:0000000007358039

1.

CHECK ENGINE COOLANT TEMPERATURE (ECT) SENSOR

1. Turn ignition switch OFF.

2. Disconnect ECT sensor harness connector.

3. Remove ECT sensor. Refer to 

CO-30, "Removal and Installation"

.

4. Check resistance between ECT sensor terminals by heating

with hot water as shown in the figure.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Proceed to 

EC-131, "Diagnosis Procedure"

.

2.

CHECK INTERMITTENT INCIDENT

Check intermittent incident. Refer to 

GI-37, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Proceed to 

EC-131, "Diagnosis Procedure"

.

Terminals

Condition

Resistance (k

Ω

)

1 and 2

Temperature [

°

C (

°

F)]

20 (68)

2.10 – 2.90

50 (122)

0.68 – 1.00

90 (194)

0.236 – 0.260

JMBIA0080ZZ

August 2012

2012 Pathfinder

P0116 ECT SENSOR

EC-131

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Diagnosis Procedure

INFOID:0000000007358040

1.

CHECK ENGINE COOLANT TEMPERATURE (ECT) SENSOR

Check ECT sensor. Refer to 

EC-131, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace ECT sensor. Refer to 

CO-30, "Removal and Installation"

.

2.

CHECK INTERMITTENT INCIDENT

Check intermittent incident. Refer to 

GI-37, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000007358041

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. Refer to 

CO-

30, "Removal and Installation"

.

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

August 2012

2012 Pathfinder

EC-132

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

P0117, P0118 ECT SENSOR

P0117, P0118 ECT SENSOR

Component Description

INFOID:0000000007358042

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>

*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.

CAUTION:

Never use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-

age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

On Board Diagnosis Logic

INFOID:0000000007358043

These self-diagnoses have the one trip detection logic.

FAIL-SAFE MODE

When the malfunction is detected, the ECM enters fail-safe mode and the MIL illuminate.

SEF594K

Engine coolant temperature

°

C (

°

F)

Voltage* V

Resistance k

Ω

-10 (14)

4.4

7.0 - 11.4

20 (68)

3.5

2.1 - 2.9

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
0117

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
0118

Engine coolant tem-
perature sensor cir-
cuit high input

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

August 2012

2012 Pathfinder

P0117, P0118 ECT SENSOR

EC-133

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

DTC Confirmation Procedure

INFOID:0000000007358044

1. If DTC Confirmation Procedure has been previously conducted, always perform the following before con-

ducting the next step.

a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and wait at least 5 seconds.
3. Check DTC.
4. If DTC is detected, go to 

EC-133, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000007358045

1.

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

2. Loosen and retighten three ground screws on the body. Refer to 

EC-97, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK ECT SENSOR POWER SUPPLY CIRCUIT

1. Disconnect engine coolant temperature (ECT) sensor harness

connector.

2. Turn ignition switch ON.

Detected items

Engine operating condition in fail-safe mode

Engine coolant temper-

ature sensor circuit

Engine coolant temperature will be determined by ECM based on the following condition.
CONSULT displays the engine coolant temperature decided by ECM.

Condition

Engine coolant temperature decided 

(CONSULT display)

Just as ignition switch is turned ON or START

40

°

C (104

°

F)

Approx. 4 minutes or more after engine starting

80

°

C (176

°

F)

Except as shown above

40 - 80

°

C (104 - 176

°

F)

(Depends on the time)

When the fail-safe system for engine coolant temperature sensor is activated, the cooling fan operates while 
engine is running.

BBIA0539E

BBIA0542E

August 2012

2012 Pathfinder

EC-134

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

P0117, P0118 ECT SENSOR

3. Check voltage between ECT sensor terminal 1 and ground with

CONSULT or tester.

OK or NG

OK

>> GO TO 3.

NG

>> 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 harness continuity between ECT sensor terminal 2 and ECM terminal 67.

Refer to Wiring Diagram.

4. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 4.

NG

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

4.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EC-134, "Component Inspection"

.

OK or NG

OK

>> GO TO 5.

NG

>> Replace engine coolant temperature sensor. Refer to 

CO-30, "Removal and Installation"

.

5.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-37, "Intermittent Incident"

.

>>

INSPECTION END

Component Inspection

INFOID:0000000007358046

ENGINE COOLANT TEMPERATURE SENSOR

1. Check resistance between engine coolant temperature sensor

terminals 1 and 2 as shown in the figure.

Voltage: Approximately 5V

PBIB0080E

Continuity should exist.

PBIB2005E

August 2012

2012 Pathfinder

P0117, P0118 ECT SENSOR

EC-135

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

<Reference data>

2. If NG, replace engine coolant temperature sensor. Refer to 

CO-

30, "Removal and Installation"

.

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

August 2012

2012 Pathfinder

EC-136

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

P0122, P0123 TP SENSOR

P0122, P0123 TP SENSOR

Component Description

INFOID:0000000007358047

Electric throttle control actuator consists of throttle control motor,

throttle position sensor, etc. The throttle position sensor responds to

the throttle valve movement. 

The throttle position sensor has the two sensors. These sensors are

a kind of potentiometer which transform the throttle valve position

into output voltage, and emit the voltage signal to the ECM. The

ECM judges the current opening angle of the throttle valve from

these signals and controls the throttle valve opening angle in

response to driving conditions via the throttle control motor.

On Board Diagnosis Logic

INFOID:0000000007358048

These self-diagnoses have the one trip detection logic.

FAIL-SAFE MODE

When the malfunction is detected, ECM enters fail-safe mode and the MIL illuminate.

DTC Confirmation Procedure

INFOID:0000000007358049

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 10V at idle.

1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to 

EC-136, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000007358050

1.

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

PBIB0145E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0122
0122

Throttle position sensor 
2 circuit low input

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

• Harness or connectors

(The TP sensor 2 circuit is open or short-
ed.)
(The APP sensor 2 circuit is shorted.)

• Electric throttle control actuator

(TP sensor 2)

• Accelerator pedal position sensor

(APP sensor 2)

P0123
0123

Throttle position sensor 
2 circuit high input

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

Engine operation condition in fail-safe mode

The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10 
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor. 

August 2012

2012 Pathfinder