Infiniti FX35 / FX45. Manual - part 360

DTC P0122, P0123 TP SENSOR

EC-201

< SERVICE INFORMATION >

[VQ35DE]

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1.

Disconnect electric throttle control actuator harness connector.

2.

Turn ignition switch ON.

3.

Check voltage between electric throttle control actuator terminal
1 and ground with CONSULT-III or tester.

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 3.

3.

CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-II

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between electric throttle control actuator terminal 1 and ECM terminal 47.
Refer to Wiring Diagram.

OK or NG

OK

>> GO TO 4.

NG

>> Repair open circuit.

4.

CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-III

Check the following.
• Harness for short to power and short to ground, between the following terminals.

OK or NG

OK

>> GO TO 5.

NG

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

5.

CHECK APP SENSOR

Refer to 

EC-517, "Component Inspection"

.

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 6.

6.

REPLACE ACCELERATOR PEDAL ASSEMBLY

1.

Replace accelerator pedal assembly.

2.

Perform 

EC-85, "Accelerator Pedal Released Position Learning"

.

3.

Perform 

EC-85, "Throttle Valve Closed Position Learning"

.

4.

Perform 

EC-85, "Idle Air Volume Learning"

.

PBIB1557E

Voltage: Approximately 5V

PBIB0082E

Continuity should exist.

ECM terminal

Sensor terminal

Reference Wiring Diagram

47

Electric throttle control actuator terminal 1

EC-199

91

APP sensor terminal 4

EC-513

EC-202

< SERVICE INFORMATION >

[VQ35DE]

DTC P0122, P0123 TP SENSOR

>> INSPECTION END

7.

CHECK THROTTLE POSITION SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between electric throttle control actuator terminal 5 and ECM terminal 66.
Refer to Wiring Diagram.

4.

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

OK or NG

OK

>> GO TO 8.

NG

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

8.

CHECK THROTTLE POSITION SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between ECM terminal 69 and electric throttle control actuator terminal 2.
Refer to Wiring Diagram.

2.

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

OK or NG

OK

>> GO TO 9.

NG

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

9.

CHECK THROTTLE POSITION SENSOR

Refer to 

EC-202, "Component Inspection"

.

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 10.

10.

REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR

1.

Replace the electric throttle control actuator.

2.

Perform 

EC-85, "Throttle Valve Closed Position Learning"

.

3.

Perform 

EC-85, "Idle Air Volume Learning"

.

>> INSPECTION END

11.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-139

.

>> INSPECTION END

Component Inspection

INFOID:0000000001326026

THROTTLE POSITION SENSOR

1.

Reconnect all harness connectors disconnected.

2.

Perform 

EC-85, "Throttle Valve Closed Position Learning"

.

3.

Turn ignition switch ON.

4.

Set selector lever to D position. 

Continuity should exist.

Continuity should exist.

DTC P0122, P0123 TP SENSOR

EC-203

< SERVICE INFORMATION >

[VQ35DE]

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5.

Check voltage between ECM terminals 50 (TP sensor 1signal),
69 (TP sensor 2signal) and body ground under the following
conditions.

6.

If NG, replace electric throttle control actuator and go to the next
step.

7.

Perform 

EC-85, "Throttle Valve Closed Position Learning"

.

8.

Perform 

EC-85, "Idle Air Volume Learning"

.

Removal and Installation

INFOID:0000000001326027

ELECTRIC THROTTLE CONTROL ACTUATOR

Refer to 

EM-19

.

Terminal

Accelerator pedal

Voltage

50
(Throttle position sensor 1)

Fully released

More than 0.36V

Fully depressed

Less than 4.75V

69
 (Throttle position sensor 2)

Fully released

Less than 4.75V

Fully depressed

More than 0.36V

PBIB1608E

EC-204

< SERVICE INFORMATION >

[VQ35DE]

DTC P0125 ECT SENSOR

DTC P0125 ECT SENSOR

Component Description

INFOID:0000000001326028

NOTE:
If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117 or
P0118. Refer to 

EC-193

.

The engine coolant temperature (ECT) 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 thermistor decreases as temperature increases.

<Reference data>

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

On Board Diagnosis Logic

INFOID:0000000001326029

DTC Confirmation Procedure

INFOID:0000000001326030

CAUTION:

Be careful not to overheat engine.
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.

 WITH CONSULT-III

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT-III.

3.

Check that “COOLAN TEMP/S” is above 10

°

C (50

°

F).

If it is above 10

°

C (50

°

F), the test result will be OK.

If it is below 10

°

C (50

°

F), go to following step.

4.

Start engine and run it for 65 minutes at idle speed.

SEF594K

Engine coolant 

temperature

°

C (

°

F)

Voltage*

V

Resistance

k

Ω

-10 (14)

4.4

7.0 - 11.4s

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

P0125
0125

Insufficient engine cool-
ant temperature for 
closed loop fuel control

• Voltage sent to ECM from the sensor is not 

practical, even when some time has passed 
after starting the engine.

• Engine coolant temperature is insufficient for 

closed loop fuel control.

• Harness or connectors

(High resistance in the circuit)

• Engine coolant temperature sensor
• Thermostat