Infiniti FX35, FX50 (S51). Manual - part 884

P2122, P2123 APP SENSOR

EC-1077

< DTC/CIRCUIT DIAGNOSIS >

[VK50VE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

NO

>> GO TO 2.

2.

REPLACE ACCELERATOR PEDAL ASSEMBLY

1.

Replace accelerator pedal assembly.

2.

Perform 

EC-1077, "Special Repair Requirement"

.

>> INSPECTION END

Special Repair Requirement

INFOID:0000000005237578

1.

PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING

Refer to 

EC-581, "ACCELERATOR PEDAL RELEASED POSITION LEARNING : Special Repair Require-

ment"

.

>> GO TO 2.

2.

PERFORM THROTTLE VALVE CLOSED POSITION LEARNING

Refer to 

EC-581, "THROTTLE VALVE CLOSED POSITION LEARNING : Special Repair Requirement"

.

>> GO TO 3.

3.

PERFORM IDLE AIR VOLUME LEARNING

Refer to 

EC-582, "IDLE AIR VOLUME LEARNING : Special Repair Requirement"

.

>> END

EC-1078

< DTC/CIRCUIT DIAGNOSIS >

[VK50VE]

P2127, P2128 APP SENSOR

P2127, P2128 APP SENSOR

Description

INFOID:0000000005237579

The accelerator pedal position sensor is installed on the accelerator
pedal assembly. The sensor detects the accelerator position and
sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometer which transform the accelerator pedal
position into output voltage, and emit 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 engine operations such as fuel cut.

DTC Logic

INFOID:0000000005237580

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting 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 8 V 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-1079, "Diagnosis Procedure"

.

NO

>> INSPECTION END

PBIB1741E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P2127

Accelerator pedal position 
sensor 2 circuit low input

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

• Harness or connectors

(Accelerator pedal position sensor 2 circuit is open or 
shorted.)
(Battery current sensor circuit is shorted.)
[Camshaft position sensor (bank 1) circuit is shorted.]
(Crankshaft position sensor circuit is shorted.)
(EVAP control system pressure sensor circuit is 
shorted.)
[EVT control position sensor (bank 1) circuit is short-
ed.]
(Manifold absolute pressure sensor circuit is short-
ed.)

• Accelerator pedal position sensor (APP sensor 2)
• Battery current sensor
• Camshaft position sensor (bank 1)
• Crankshaft position sensor
• EVAP control system pressure sensor
• Exhaust valve timing control position sensor (bank 1)
• Manifold absolute pressure sensor

P2128

Accelerator pedal position 
sensor 2 circuit high input

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

P2127, P2128 APP SENSOR

EC-1079

< DTC/CIRCUIT DIAGNOSIS >

[VK50VE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Diagnosis Procedure

INFOID:0000000005237581

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection M95. Refer to Ground Inspection in 

GI-39, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK ACCELERATOR PEDAL POSITION SENSOR 2 POWER SUPPLY CIRCUIT-I

1.

Disconnect accelerator pedal position (APP) sensor harness connector.

2.

Turn ignition switch ON.

3.

Check the voltage between APP sensor harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> GO TO 3.

3.

CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check the continuity between APP sensor harness connector and ECM harness connector.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors M6, E106
• Harness for open or short between ECM and APP sensor

>> Repair open circuit.

5.

CHECK SENSOR POWER SUPPLY CIRCUIT

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

APP sensor

Ground

Voltage (V)

Connector

Terminal

E112

(Without ICC)

6

Ground

Approx. 5

E116

(With ICC)

3

APP sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

E112

(Without ICC)

6

M160

99

Existed

E116

(With ICC)

3

EC-1080

< DTC/CIRCUIT DIAGNOSIS >

[VK50VE]

P2127, P2128 APP SENSOR

Is the inspection result normal?

YES

>> GO TO 6.

NO

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

6.

CHECK COMPONENTS

Check the following.
• Crankshaft position sensor (Refer to 

EC-876, "Component Inspection"

.)

• Camshaft position sensor (bank 1) (Refer to 

EC-881, "Component Inspection"

.)

• Exhaust valve timing control position sensor (bank 1) (Refer to 

EC-978, "Component Inspection"

.)

• EVAP control system pressure sensor (Refer to 

EC-917, "Component Inspection"

.)

• Manifold absolute pressure sensor (Refer to 

EC-785, "Component Inspection"

.)

Is the inspection result normal?

YES

>> GO TO 13.

NO

>> Replace malfunctioning component.

7.

CHECK APP SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check the continuity between APP 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 9.

NO

>> GO TO 8.

8.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors M6, E106
• Harness for open or short between ECM and APP sensor

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

9.

CHECK APP SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check the continuity between APP sensor harness connector and ECM harness connector.

ECM

Sensor

Connector

Terminal

Name

Connector

Terminal

F111

87

Crankshaft position sensor

F2

1

91

Camshaft position sensor (bank 1)

F84

1

EVT control position sensor (bank 1)

F59

1

95

Battery current sensor

E21

1

EVAP control system pressure sensor

B252

3

Manifold absolute pressure sensor

F65

1

M160

99

APP sensor (Without ICC)

E112

6

APP sensor (with ICC)

E116

3

APP sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

E112

(Without ICC)

2

M160

115

Existed

E116

(With ICC)

2