Infiniti FX35 / FX45. Manual - part 416

DTC P0643 SENSOR POWER SUPPLY

EC-425

< SERVICE INFORMATION >

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Wiring Diagram

INFOID:0000000001326273

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

TBWM1400E

EC-426

< SERVICE INFORMATION >

[VQ35DE]

DTC P0643 SENSOR POWER SUPPLY

Diagnosis Procedure

INFOID:0000000001326274

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten ground screw on the body. Refer to 

EC-144, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT-I

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

48

LG

Sensor power supply
(EVAP control system pres-
sure sensor)

[Ignition switch: ON]

Approximately 5V

49

PU

Sensor power supply
(Refrigerant pressure sen-
sor)

[Ignition switch: ON]

Approximately 5V

68

BR

Sensor power supply
(Power steering pressure 
sensor)

[Ignition switch: ON]

Approximately 5V

82

B/W

Sensor ground
(APP sensor 1, ASCD steer-
ing switch, ICC steering 
switch)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 0V

83

G/OR

Sensor ground
(APP sensor 2)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 0V

90

L/B

Sensor power supply
(APP sensor 1)

[Ignition switch: ON]

Approximately 5V

91

G

Sensor power supply
(APP sensor 2)

[Ignition switch: ON]

Approximately 5V

98

Y/R

Accelerator pedal position 
sensor 2

[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully released

0.15 - 0.60V

[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully depressed

1.95 - 2.40V

106

OR

Accelerator pedal position 
sensor 1

[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully released

0.5 - 1.0V

[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully depressed

3.9 - 4.7V

PBIB2625E

DTC P0643 SENSOR POWER SUPPLY

EC-427

< SERVICE INFORMATION >

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1.

Disconnect accelerator pedal position (APP) sensor harness
connector.

2.

Turn ignition switch ON.

3.

Check voltage between APP sensor terminal 6 and ground with
CONSULT-III or tester.

OK or NG

OK

>> GO TO 5.

NG

>> GO TO 3.

3.

CHECK SENSOR POWER SUPPLY CIRCUITS

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

OK or NG

OK

>> GO TO 6.

NG

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

4.

CHECK COMPONENTS

Check the following.
• Refrigerant pressure sensor (Refer to 

ATC-69, "Magnet Clutch Circuit"

.)

• Power steering pressure sensor (Refer to 

EC-416, "Component Inspection"

.)

• EVAP control system pressure sensor (Refer to 

EC-373, "Component Inspection"

.)

OK or NG

OK

>> GO TO 7.

NG

>> Replace malfunctioning component.

5.

CHECK ACCELERATOR PEDAL POSITION SENSOR

Refer to 

EC-511, "Component Inspection"

.

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

6.

REPLACE ACCELERATOR PEDAL ASSEMBLY

1.

Replace accelerator pedal assembly.

2.

Perform 

EC-85, "Accelerator Pedal Released Position Learning"

.

3.

Perform 

EC-85, "Throttle Valve Closed Position Learning"

.

4.

Perform 

EC-85, "Idle Air Volume Learning"

.

PBIB1580E

Voltage: Approximately 5V

PBIB0914E

ECM terminal

Sensor terminal

Reference Wiring Diagram

90

APP sensor terminal 6

EC-508

49

Refrigerant pressure sensor terminal 1

EC-582

68

PSP sensor terminal 1

EC-414

48

EVAP control system pressure sensor terminal 3

EC-377

EC-428

< SERVICE INFORMATION >

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DTC P0643 SENSOR POWER SUPPLY

>> INSPECTION END

7.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-139

.

>> INSPECTION END