Infiniti FX35, FX50 (S51). Manual - part 705

P0643 SENSOR POWER SUPPLY

EC-361

< 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 9.

NO

>> GO TO 8.

8.

REPLACE ACCELERATOR PEDAL ASSEMBLY

1.

Replace accelerator pedal assembly.

2.

Go to 

EC-445, "Special Repair Requirement"

.

>> INSPECTION END

9.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

EC-362

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P0850 PNP SWITCH

P0850 PNP SWITCH

Description

INFOID:0000000005236952

When the selector lever position is P or N, park/neutral position (PNP) signal from the TCM is sent to ECM.

DTC Logic

INFOID:0000000005236953

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

INSPECTION START

Will CONSULT-III be used?

Will CONSULT-III be used?

YES

>> GO TO 2.

NO

>> GO TO 5.

2.

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.

>> GO TO 3.

3.

CHECK PNP SIGNAL

With CONSULT-III

1.

Turn ignition switch ON.

2.

Select “P/N POSI SW” in “DATA MONITOR” mode with CONSULT-III. Then check the “P/N POSI SW” sig-
nal under the following conditions.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Go to 

EC-363, "Diagnosis Procedure"

.

4.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Select “DATA MONITOR” mode with CONSULT-III.

2.

Start engine and warm it up to normal operating temperature.

3.

Maintain the following conditions for at least 50 consecutive seconds.

CAUTION:

Always drive vehicle at a safe speed.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0850

Park/neutral position 
switch

The signal of the park/neutral position (PNP) 
signal does not change during driving after the 
engine is started.

• Harness or connectors

(The PNP signal circuit is open or short-
ed.)

• TCM

Position (Selector lever)

Known-good signal

N or P position

ON

Except above position

OFF

ENG SPEED

1,400 - 6,375 rpm

COOLAN TEMP/S

More than 70 

°

C (158 

°

F)

B/FUEL SCHDL

2.0 - 31.8 msec

P0850 PNP SWITCH

EC-363

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

4.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-363, "Diagnosis Procedure"

.

NO

>> INSPECTION END

5.

PERFORM COMPONENT FUNCTION CHECK

With GST

Perform component function check. Refer to 

EC-363, "Component Function Check"

.

NOTE:
Use component function check to check the overall function of the PNP signal circuit. During this check, a 1st
trip DTC might not be confirmed.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-363, "Diagnosis Procedure"

.

Component Function Check

INFOID:0000000005236954

1.

PERFORM COMPONENT FUNCTION CHECK

With GST

1.

Turn ignition switch ON.

2.

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

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-363, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000005236955

1.

CHECK DTC WITH TCM

Refer to 

TM-62, "CONSULT-III Function (TRANSMISSION)"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace malfunctioning part.

2.

CHECK STARTING SYSTEM

Turn ignition switch OFF, then turn it to START.

Does starter motor operate?

YES

>> GO TO 3.

NO

>> Check DTC with BCM. Refer to 

BCS-17, "COMMON ITEM : CONSULT-III Function (BCM - COM-

MON ITEM)"

.

3.

CHECK PARK/NEUTRAL POSITION (PNP) SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect A/T assembly harness connector.

3.

Disconnect ECM harness connector.

4.

Check the continuity between A/T assembly harness connector and ECM harness connector.

VHCL SPEED SE

More than 64 km/h (40 mph)

Selector lever

Suitable position

ECM

Condition

Voltage (V)

Connector

+

–

Terminal

Terminal

M107

109

128

Selector lever

P or N

Battery voltage

Except above

Approx. 0

EC-364

< DTC/CIRCUIT DIAGNOSIS >

[VQ35HR]

P0850 PNP SWITCH

5.

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

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors F1, E3
• Harness connectors E106, M6
• Harness for open or short between A/T assembly and ECM

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

5.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-36, "Intermittent Incident"

.

>> INSPECTION END

A/T assembly

ECM

Continuity

Connector

Terminal

Connector

Terminal

F51

9

M107

109

Existed