Nissan Maxima. Manual - part 430

EC-204

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0117, P0118 ECT SENSOR

P0117, P0118 ECT SENSOR

Description

INFOID:0000000010094909

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 52 (Sensor ground).

DTC Logic

INFOID:0000000010094910

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.

>> 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-205, "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

2.1 - 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

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.

P0117, P0118 ECT SENSOR

EC-205

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Diagnosis Procedure

INFOID:0000000010094911

Regarding Wiring Diagram information, refer to 

EC-554, "Wiring Diagram"

.

1.

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

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

GI-44, "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, 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, short to ground or short to power in harness or connectors.

4.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EC-205, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace engine coolant temperature sensor. Refer to 

CO-24, "Removal and Installation"

.

5.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-41, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000010094912

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-24, "Removal and Installation"

.

ECT sensor

Ground

Voltage

Connector

Terminal

F11

1

Ground

Approx. 5 V

PBIB0080E

ECT sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

F11

2

F13

52

Existed

EC-206

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0117, P0118 ECT SENSOR

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-24, "Removal and Installation"

.

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

PBIB2005E

P0122, P0123 TP SENSOR

EC-207

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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P0122, P0123 TP SENSOR

Description

INFOID:0000000010094913

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 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 sig-

nals and controls the throttle valve opening angle in response to

driving conditions via the throttle control motor.

DTC Logic

INFOID:0000000010094914

DTC DETECTION LOGIC

NOTE:

If DTC P0122 or P0123 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.

Refer to 

EC-394, "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.

TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 8 V at idle.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1. Start engine and let it idle for 1 second.

2. Check DTC.
Is DTC detected?

YES

>> Go to 

EC-207, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010094915

Regarding Wiring Diagram information, refer to 

EC-554, "Wiring Diagram"

.

1.

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

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

GI-44, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

PBIB0145E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0122

Throttle position sensor 
2 circuit low input

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

• Harness or connectors

(TP sensor 2 circuit is open or shorted.)

• Electric throttle control actuator

(TP sensor 2)

P0123

Throttle position sensor 
2 circuit high input

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