Infiniti QX56 (JA60). Manual - part 428

EC-364

< COMPONENT DIAGNOSIS >

[VK56DE]

P2118 THROTTLE CONTROL MOTOR

2.

CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT

1. Disconnect electric throttle control actuator (1) harness connec-

tor.

-

Illustration shows the view with intake air duct removed.

2. Disconnect ECM harness connector.

3. Check harness continuity between the following terminals.

Refer to Wiring Diagram.

4. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace.

3.

CHECK THROTTLE CONTROL MOTOR

Refer to 

EC-364, "Component Inspection"

.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 5.

4.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-35, "How to Check Terminal"

 and 

GI-38, "Intermittent Incident"

.

OK or NG

OK

>> GO TO 5.

NG

>> Repair or replace harness or connectors.

5.

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

Component Inspection

INFOID:0000000005149435

THROTTLE CONTROL MOTOR

1. Disconnect electric throttle control actuator harness connector.
2. Check resistance between terminals 5 and 6.

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

step.

4. Perform 

EC-18, "Throttle Valve Closed Position Learning"

.

5. Perform 

EC-18, "Idle Air Volume Learning"

.

Electric throttle control 

actuator terminal

ECM terminal

Continuity

5

5

Should not exist

4

Should exist

6

5

Should exist

4

Should not exist

BBIA0776E

Resistance: Approximately 1 - 15 

Ω [at 25 °C (77°F)]

PBIB2066E

P2119 ELECTRIC THROTTLE CONTROL ACTUATOR

EC-365

< COMPONENT DIAGNOSIS >

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P2119 ELECTRIC THROTTLE CONTROL ACTUATOR

Component Description

INFOID:0000000005149436

Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.

The throttle control motor is operated by the ECM and it opens and closes the throttle valve.

The throttle position sensor detects the throttle valve position, and the opening and closing speed of the throt-

tle valve and feeds 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.

On Board Diagnosis Logic

INFOID:0000000005149437

This self-diagnosis has 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:0000000005149438

NOTE:

• Perform PROCEDURE FOR MALFUNCTION A AND B first. If the DTC cannot be confirmed, perform

PROCEDURE FOR MALFUNCTION C.

• 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.

PROCEDURE FOR MALFUNCTION A AND B

1. Turn ignition switch ON and wait at least 1 second.
2. Shift selector lever to D position and wait at least 3 seconds.
3. Shift selector lever to P or N position.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON and wait at least 1 second.
6. Shift selector lever to D position and wait at least 3 seconds.
7. Shift selector lever to P or N position.
8. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
9. Check DTC.
10. If DTC is detected, go to 

EC-366, "Diagnosis Procedure"

.

PROCEDURE FOR MALFUNCTION C

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P2119
2119

Electric throttle control 
actuator

A)

Electric throttle control actuator does not func-
tion properly due to the return spring malfunc-
tion.

• Electric throttle control actuator

B)

Throttle valve opening angle in fail-safe mode is 
not in specified range.

C)

ECM detect the throttle valve is stuck open.

Detected items

Engine operating condition in fail-safe mode

Malfunction A

The ECM controls the electric throttle actuator by regulating the throttle opening around the idle position. 
The engine speed will not rise more than 2,000 rpm.

Malfunction B

ECM controls the electric throttle control actuator by regulating the throttle opening to 20 degrees or less.

Malfunction C

While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or more.

EC-366

< COMPONENT DIAGNOSIS >

[VK56DE]

P2119 ELECTRIC THROTTLE CONTROL ACTUATOR

1. Turn ignition switch ON and wait at least 1 second.
2. Shift selector lever to D position and wait at least 3 seconds.
3. Shift selector lever to P position.
4. Start engine and let it idle for 3 seconds.
5. Check DTC.
6. If DTC is detected, go to 

EC-366, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000005149439

1.

CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY

1. Remove the intake air duct.

2. Check if a foreign matter is caught between the throttle valve

and the housing.

OK or NG

OK

>> GO TO 2.

NG

>> Remove the foreign matter and clean the electric throttle

control actuator inside.

2.

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

BBIA0364E

P2122, P2123 APP SENSOR

EC-367

< COMPONENT DIAGNOSIS >

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P2122, P2123 APP SENSOR

Component Description

INFOID:0000000005149440

The accelerator pedal position sensor is installed on the upper end

of the accelerator pedal assembly. The sensor detects the accelera-

tor position and sends a signal to the ECM.

Accelerator pedal position sensor has two sensors. These sensors

are a kind of potentiometers which transform the accelerator pedal

position into output voltage, and emit the voltage signal to the ECM.

In addition, these sensors detect the opening and closing speed of

the accelerator pedal and feed the voltage signals to the ECM. The

ECM judges the current opening angle of the accelerator pedal from

these signals and controls the throttle control motor based on these

signals.

Idle position of the accelerator pedal is determined by the ECM

receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-

ation such as fuel cut.

On Board Diagnosis Logic

INFOID:0000000005149441

These self-diagnoses have the one trip detection logic.

NOTE:

If DTC P2122 or P2123 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.

Refer to 

EC-289

.

FAIL-SAFE MODE

When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.

DTC Confirmation Procedure

INFOID:0000000005149442

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 8 V at idle.

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

2. Check DTC.

3. If DTC is detected, go to 

EC-367, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000005149443

1.

CHECK GROUND CONNECTIONS

PBIB1741E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P2122
2122

Accelerator pedal position 
sensor 1 circuit low input

An excessively low voltage from the APP sen-
sor 1 is sent to ECM.

• Harness or connectors

(The APP sensor 1 circuit is open or 
shorted.)

• Accelerator pedal position sensor

(Accelerator pedal position sensor 1)

P2123
2123

Accelerator pedal position 
sensor 1 circuit high input

An excessively high voltage from the APP sen-
sor 1 is sent to ECM.

Engine operating 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.