Infiniti FX35, FX50 (S51). Manual - part 725

P1805 BRAKE SWITCH

EC-441

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace stop lamp switch.

Terminals

Condition

Continuity

1 and 2

Brake pedal

Fully released

Not existed

Slightly depressed

Existed

EC-442

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P2122, P2123 APP SENSOR

P2122, P2123 APP SENSOR

Description

INFOID:0000000005237051

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 potentiometer 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 sends 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 opera-
tions such as fuel cut.

DTC Logic

INFOID:0000000005237052

DTC DETECTION LOGIC

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

EC-359, "DTC 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 10 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-442, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000005237053

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection M95. Refer to Ground Inspection in 

GI-39, "Circuit Inspection"

.

PBIB1741E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P2122

Accelerator pedal posi-
tion (APP) sensor 1 cir-
cuit low input

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

• Harness or connectors

(APP sensor 1 circuit is open or shorted.)

• Accelerator pedal position sensor

(APP sensor 1)

P2123

Accelerator pedal posi-
tion (APP) sensor 1 cir-
cuit high input

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

P2122, P2123 APP SENSOR

EC-443

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK ACCELERATOR PEDAL POSITION (APP) SENSOR 1 POWER SUPPLY CIRCUIT

1.

Disconnect 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 4.

NO

>> GO TO 3.

3.

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.

4.

CHECK APP SENSOR 1 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 6.

NO

>> GO TO 5.

5.

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.

6.

CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

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

APP sensor

Ground

Voltage (V)

Connector

Terminal

E112

(Without ICC)

5

Ground

Approx. 5

E116

(With ICC)

APP sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

E112

(Without ICC)

4

M107

100

Existed

E116

(With ICC)

1

EC-444

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P2122, P2123 APP SENSOR

2.

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.
• 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.

8.

CHECK APP SENSOR

Refer to 

EC-444, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 10.

NO

>> GO TO 9.

9.

REPLACE ACCELERATOR PEDAL ASSEMBLY

1.

Replace accelerator pedal assembly.

2.

Go to 

EC-445, "Special Repair Requirement"

.

>> INSPECTION END

10.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005237054

1.

CHECK ACCELERATOR PEDAL POSITION (APP) 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

APP sensor

ECM

Continuity

Connector

Terminal

Connector

Terminal

E112

(Without ICC)

3

M107

97

Existed

E116

(With ICC)

4

ECM

Condition

Voltage (V)

Connector

+

–

Terminal

Terminal

M107

97 (APP sensor 1)

100

Accelerator pedal

Fully released

0.45 - 1.0

Fully depressed

4.4 - 4.8

98 (APP sensor 2)

104

Fully released

0.22 - 0.50

Fully depressed

2.1 - 2.5