Infiniti G37 Coupe. Manual - part 501

P0117, P0118 ECT SENSOR

EC-185

< COMPONENT DIAGNOSIS >

[VQ37VHR]

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EC

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Is DTC detected?

YES

>> Go to 

EC-185, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000001734014

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection M95. Refer to Ground Inspection in 

GI-41, "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 4.

NO

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors F106, F107
• Harness for open or short between engine coolant temperature sensor and ECM

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

4.

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 5.

NO

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

5.

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EC-186, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Replace engine coolant temperature sensor.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-38, "Intermittent Incident"

.

>> INSPECTION END

ECT sensor

Ground

Voltage

Connector

Terminal

F17

1

Ground

Approx. 5V

ECT sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

F17

2

F102

84

Existed

EC-186

< COMPONENT DIAGNOSIS >

[VQ37VHR]

P0117, P0118 ECT SENSOR

Component Inspection

INFOID:0000000001734015

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 by heating with hot water as shown in the figure.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace engine coolant temperature sensor.

Terminals

Condition

Resistance

1 and 2

Temperature 

°

C (

°

F)

20 (68)

2.37 - 2.63 k

Ω

50 (122)

0.68 - 1.00 k

Ω

90 (194)

0.236 - 0.260 k

Ω

JMBIA0080ZZ

P0122, P0123, P0227, P0228 TP SENSOR

EC-187

< COMPONENT DIAGNOSIS >

[VQ37VHR]

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P0122, P0123, P0227, P0228 TP SENSOR

Description

INFOID:0000000001734016

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 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.

DTC Logic

INFOID:0000000001734017

DTC DETECTION LOGIC

NOTE:
If DTC P0122, P0123, P0227 or P0228 is displayed with DTC P0643, first perform the trouble diagnosis
for DTC P0643. Refer to 

EC-358, "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 10V 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-188, "Diagnosis Procedure"

.

NO

>> INSPECTION END

PBIB0145E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0122

Throttle position sensor 
2 (bank 1) circuit low in-
put

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 (bank 1) circuit high in-
put

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

P0227

Throttle position sensor 
2 (bank 2) circuit low in-
put

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

P0228

Throttle position sensor 
2 (bank 2) circuit high in-
put

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

EC-188

< COMPONENT DIAGNOSIS >

[VQ37VHR]

P0122, P0123, P0227, P0228 TP SENSOR

Diagnosis Procedure

INFOID:0000000001734018

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection M95. Refer to Ground Inspection in 

GI-41, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT

1.

Disconnect electric throttle control actuator harness connector.

2.

Turn ignition switch ON.

3.

Check the voltage between electric throttle control actuator 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 THROTTLE POSITION SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check the continuity between electric throttle control actuator harness connector and ECM harness con-
nector.

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 THROTTLE POSITION SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check the continuity between electric throttle control actuator harness connector and ECM harness con-
nector.

2.

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

Is the inspection result normal?

YES

>> GO TO 5.

NO

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

5.

CHECK THROTTLE POSITION SENSOR

Refer to 

EC-189, "Component Inspection"

.

DTC

Electric throttle control actuator

Ground

Voltage

Bank

Connector

Terminal

P0122, P0123

1

F6

6

Ground

Approx. 5V

P0227, P0228

2

F27

1

DTC

Electric throttle control actuator

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0122, P0123

1

F6

3

F101

40

Existed

P0227, P0228

2

F27

4

48

DTC

Electric throttle control actuator

ECM

Continuity

Bank

Connector

Terminal

Connector

Terminal

P0122, P0123

1

F6

5

F101

34

Existed

P0227, P0228

2

F27

3

35