Infiniti QX56 (JA60). Manual - part 368

EC-124

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P0117, P0118 ECT SENSOR

1. Check resistance between engine coolant temperature sensor

terminals 1 and 2 as shown in the figure.

2. If NG, replace engine coolant temperature sensor.

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

P0122, P0123 TP SENSOR

EC-125

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P0122, P0123 TP SENSOR

Component Description

INFOID:0000000005149136

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 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.

On Board Diagnosis Logic

INFOID:0000000005149137

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:0000000005149138

NOTE:

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting the next step.
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 8V at idle.

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

2. Check DTC.

3. If DTC is detected, go to 

EC-125, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000005149139

1.

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

2. Loosen and retighten three ground screws on the body.

PBIB0145E

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. 

EC-126

< COMPONENT DIAGNOSIS >

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P0122, P0123 TP SENSOR

Refer to 

EC-85, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-I

1. Disconnect electric throttle control actuator harness connector.

2. Turn ignition switch ON.

3. Check voltage between electric throttle control actuator terminal

2 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 2 and ECM terminal 47.

Refer to Wiring Diagram.

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace open circuit.

4.

CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-III

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

BBIA0354E

PBIB1480E

Voltage: Approximately 5 V

PBIB2065E

Continuity should exist.

ECM terminal

Sensor terminal

Reference Wiring Diagram

47

Electric throttle control actuator terminal 2

EC-435, "Wiring Diagram - ENGINE 

CONTROL SYSTEM -"

91

APP sensor terminal 6

P0122, P0123 TP SENSOR

EC-127

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OK or NG

OK

>> GO TO 5.

NG

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

5.

CHECK ACCELERATOR PEDAL POSITION SENSOR

Refer to 

EC-381, "Component Inspection"

.

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 6.

6.

REPLACE ACCELERATOR PEDAL ASSEMBLY

1. Replace the accelerator pedal assembly.

2. Perform 

EC-18, "Accelerator Pedal Released Position Learning"

.

3. Perform 

EC-18, "Throttle Valve Closed Position Learning"

.

4. Perform 

EC-18, "Idle Air Volume Learning"

.

>> 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 4 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 3.

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-128, "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-18, "Throttle Valve Closed Position Learning"

.

3. Perform 

EC-18, "Idle Air Volume Learning"

.

>> INSPECTION END

11.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-35, "How to Check Terminal"

 and 

GI-38, "Intermittent Incident"

.

Continuity should exist.

Continuity should exist.