Infiniti QX56 (Z62). Manual - part 623

EC-470

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

P2122, P2123 APP SENSOR

Replace accelerator pedal assembly. Refer to 

ACC-3, "MODELS WITHOUT DISTANCE CONTROL ASSIST

SYSTEM : Removal and Installation"

 (Without distance control assist system) or 

ACC-4, "MODELS WITH

DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation"

 (With distance control assist system).

>> INSPECTION END

9.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection (Accelerator Pedal Position Sensor)

INFOID:0000000006217974

1.

CHECK ACCELERATOR PEDAL POSITION SENSOR

1.

Turn ignition switch OFF.

2.

Reconnect all harness connectors disconnected.

3.

Turn ignition switch ON.

4.

Check the voltage ECM harness connector terminals under the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 2.

2.

REPLACE ACCELERATOR PEDAL ASSEMBLY

Replace accelerator pedal assembly. Refer to 

ACC-3, "MODELS WITHOUT DISTANCE CONTROL ASSIST

SYSTEM : Removal and Installation"

 (Without distance control assist system) or 

ACC-4, "MODELS WITH

DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation"

 (With distance control assist system).

>> INSPECTION END

ECM

Condition

Voltage (V)

Connector

+

–

Terminal

Terminal

E80

136 (APP sensor 1)

140

Accelerator pedal

Fully released

0.65 - 0.87

Fully depressed

4.3 - 4.8

126 (APP sensor 2)

129

Fully released

0.28 - 0.48

Fully depressed

2.0 - 2.5

P2127, P2128 APP SENSOR

EC-471

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

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P2127, P2128 APP SENSOR

DTC Logic

INFOID:0000000006217975

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

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 8 V or more 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-471, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000006217976

1.

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 6.

NO

>> GO TO 2.

DTC No.

Trouble diagnosis name

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P2127

APP SEN 2/CIRC
(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.)
(Refrigerant pressure sensor circuit is shorted.)
(EVAP control system pressure sensor circuit is 
shorted.)

• Accelerator pedal position sensor (APP sensor 2)
• Battery current sensor
• Camshaft position sensor (bank 1)
• Crankshaft position sensor
• Refrigerant pressure sensor
• EVAP control system pressure sensor

P2128

APP SEN 2/CIRC
(Accelerator pedal position 
sensor 2 circuit high input)

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

APP sensor

Ground

Voltage (V)

Connector

Terminal

E110

(Without ICC)

1

Ground

Approx. 5

E67

(With ICC)

9

EC-472

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

P2127, P2128 APP SENSOR

2.

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 4.

NO

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.
• Loose or poor connection for each connector and harness
• Harness for open or short between ECM and APP sensor

>> Repair open circuit.

4.

CHECK SENSOR POWER SUPPLY CIRCUIT

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

Is the inspection result normal?

YES

>> GO TO 5.

NO

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

5.

CHECK COMPONENTS

Check the following.
• Crankshaft position sensor (Refer to 

EC-301, "Component Inspection (Crankshaft Position Sensor)"

.)

• Camshaft position sensor (bank 1) (Refer to 

EC-306, "Component Inspection (Camshaft Position Sensor)"

.)

• Refrigerant pressure sensor (Refer to 

EC-520, "Component Function Check"

.)

• EVAP control system pressure sensor (Refer to 

EC-335, "Component Inspection (EVAP Control System

Pressure Sensor)"

.)

Is the inspection result normal?

YES

>> GO TO 12.

NO

>> Replace malfunctioning component.

6.

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.

APP sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

E110

(Without ICC)

1

E80

131

Existed

E67

(With ICC)

9

ECM

Sensor

Connector

Terminal

Name

Connector

Terminal

F110

76

Crankshaft position sensor

F74

1

77

Camshaft position sensor (bank 1)

F84

1

E80

133

Battery current sensor

E63

2

Refrigerant pressure sensor

E77

1

EVAP control system pressure sensor

C17

3

131

APP sensor (Without ICC)

E110

1

APP sensor (with ICC)

E67

9

P2127, P2128 APP SENSOR

EC-473

< DTC/CIRCUIT DIAGNOSIS >

[VK56VD]

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4.

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

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> GO TO 7.

7.

DETECT MALFUNCTIONING PART

Check the following.
• Loose or poor connection for each connector and harness
• Harness for open or short between ECM and APP sensor

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

8.

CHECK APP SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

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

2.

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

Is the inspection result normal?

YES

>> GO TO 10.

NO

>> GO TO 9.

9.

DETECT MALFUNCTIONING PART

Check the following.
• Harness for open or short between ECM and APP sensor
• Loose or poor connection for each connector and harness

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

10.

CHECK APP SENSOR

Refer to 

EC-474, "Component Inspection (Accelerator Pedal Position Sensor)"

.

Is the inspection result normal?

YES

>> GO TO 12.

NO

>> GO TO 11.

11.

REPLACE ACCELERATOR PEDAL ASSEMBLY

Replace accelerator pedal assembly. Refer to 

ACC-3, "MODELS WITHOUT DISTANCE CONTROL ASSIST

SYSTEM : Removal and Installation"

 (Without distance control assist system) or 

ACC-4, "MODELS WITH

DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation"

 (With distance control assist system).

>> INSPECTION END

12.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

APP sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

E110

(Without ICC)

5

E80

129

Existed

E67

(With ICC)

8

APP sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

E110

(Without ICC)

6

E80

126

Existed

E67

(With ICC)

7