Infiniti FX35 / FX45. Manual - part 359

DTC P0117, P0118 ECT SENSOR

EC-197

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5.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-139

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>> INSPECTION END

Component Inspection

INFOID:0000000001326018

ENGINE COOLANT TEMPERATURE SENSOR

Check resistance between engine coolant temperature sensor termi-
nals 1 and 2 as shown in the figure.

<Reference data>

If NG, replace engine coolant temperature sensor.

Removal and Installation

INFOID:0000000001326019

ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

CO-27

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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

EC-198

< SERVICE INFORMATION >

[VQ35DE]

DTC P0122, P0123 TP SENSOR

DTC P0122, P0123 TP SENSOR

Component Description

INFOID:0000000001326020

Electric throttle control actuator consists of throttle control motor,
throttle position (TP) 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 potentiometers which transform the throttle valve position into
output voltage, and emit the voltage signal to the ECM. In addition,
these sensors detect the opening and closing speed of the throttle
valve and feed the voltage signals to the ECM. The ECM judges the
current opening angle of the throttle valve from these signals and the
ECM controls the throttle control motor to make the throttle valve
opening angle properly in response to driving condition.

CONSULT-III Reference Value in Data Monitor Mode

INFOID:0000000001326021

Specification data are reference values.

*: Throttle position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage signal.

On Board Diagnosis Logic

INFOID:0000000001326022

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 lights up.

DTC Confirmation Procedure

INFOID:0000000001326023

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

1.

Start engine and let it idle for 1 second.

2.

Check DTC.

3.

If DTC is detected, go to 

EC-200, "Diagnosis Procedure"

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PBIB0145E

MONITOR ITEM

CONDITION

SPECIFICATION

TP SEN 1-B1
TP SEN 2-B1*

• Ignition switch: ON

(Engine stopped)

• Selector lever: D

Accelerator pedal: Fully released

More than 0.36V

Accelerator pedal: Fully depressed

Less than 4.75V

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

(TP sensor 2 circuit is open or shorted.)
(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. 

DTC P0122, P0123 TP SENSOR

EC-199

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Wiring Diagram

INFOID:0000000001326024

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not 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.

TBWM0393E

EC-200

< SERVICE INFORMATION >

[VQ35DE]

DTC P0122, P0123 TP SENSOR

Diagnosis Procedure

INFOID:0000000001326025

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten ground screw on the body. Refer to 

EC-144, "Ground Inspection"

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OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-I

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

47

L

Sensor power supply (Throt-
tle position sensor)

[Ignition switch: ON]

Approximately 5V

50

W

Throttle position sensor 1

[Ignition switch: ON]
• Engine stopped
• Selector lever: D
• Accelerator pedal: Fully released

More than 0.36V

[Ignition switch: ON]
• Engine stopped
• Selector lever: D
• Accelerator pedal: Fully depressed

Less than 4.75V

66

B

Sensor ground
(Throttle position sensor)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 0V

69

R

Throttle position sensor 2

[Ignition switch: ON]
• Engine stopped
• Selector lever: D
• Accelerator pedal: Fully released

Less than 4.75V

[Ignition switch: ON]
• Engine stopped
• Selector lever: D
• Accelerator pedal: Fully depressed

More than 0.36V

91

G

Sensor power supply
(APP sensor 2)

[Ignition switch: ON]

Approximately 5V

PBIB2625E