Infiniti M45 (Y34). Manual - part 377

DTC P0117, P0118 ECT SENSOR

EC-197

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4. 

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 89.
Refer to Wiring Diagram.

4.

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

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

5. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors F261, F24

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Joint connector-30

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Harness for open and short between ECT sensor and ECM

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

6. 

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EC-197, "Component Inspection"

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OK or NG

OK

>> GO TO 7.

NG

>> Replace engine coolant temperature sensor.

7. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

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>> INSPECTION END

Component Inspection

ABS002FT

ENGINE COOLANT TEMPERATURE SENSOR

1.

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

Continuity should exist.

PBIB2005E

EC-198

DTC P0117, P0118 ECT SENSOR

<Reference data>

2.

If NG, replace engine coolant temperature sensor.

Removal and Installation

ABS002FU

ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EM-65, "CYLINDER HEAD"

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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

DTC P0122, P0123 TP SENSOR

EC-199

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DTC P0122, P0123 TP SENSOR

PFP:16119

Component Description

ABS002FV

Electric throttle control actuator consists of throttle control motor,
accelerator pedal position sensor, 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 potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, 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 sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.

CONSULT-II Reference Value in Data Monitor Mode

ABS002FW

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

ABS002FX

NOTE:
If DTC P0122, P0123 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229.
Refer to 

EC-531

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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.

PBIB0145E

MONITOR ITEM

CONDITION

SPECIFICATION

THRTL SEN 1
THRTL SEN 2*

●

Ignition switch: ON
(Engine stopped)

Accelerator pedal: Fully released

More than 0.36V

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Selector lever: D

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

●

Electric throttle control actuator
(TP 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. 

EC-200

DTC P0122, P0123 TP SENSOR

DTC Confirmation Procedure

ABS002FY

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 10V at idle.

 WITH CONSULT-II

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Start engine and let it idle for 1 second.

4.

If DTC is detected, go to 

EC-202, "Diagnostic Procedure"

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 WITH GST

Follow the procedure “WITH CONSULT-II” above.

SEF058Y