2007 INFINITI FX35 engine

DTC P0550 PSP SENSOR EC-1139
[VK45DE]
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Revision: 2006 July 2007 FX35/FX45
DTC P0550 PSP SENSORPFP:49763
Component DescriptionNBS0049W
Power steering pressure (PSP) sensor is installed to the power
steering high-pressure tube and detects a power steering load. This
sensor is a potentiometer which transforms the power steering load
into output voltage, and emits the voltage signal to the ECM. The
ECM controls the electric throttle control actuator and adjusts the
throttle valve opening angle to increase the engine speed and
adjusts the idle speed for the increased load.
CONSULT-II Reference Value in Data Monitor ModeNBS0049X
Specification data are reference values.
On Board Diagnosis LogicNBS0049Y
The MIL will not light up for this diagnosis.
NOTE:
If DTC P0550 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to
EC-1151, "
DTC P0643 SENSOR POWER SUPPLY" .
DTC Confirmation ProcedureNBS0049Z
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-1141, "
Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB1484E
MONITOR ITEM CONDITION SPECIFICATION
PW/ST SIGNAL

Engine: After warming up, idle
the engine Steering wheel: Not being turned OFF
Steering wheel: Being turned ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0550
0550 Power steering pres-
sure sensor circuit An excessively low or high voltage from the
sensor is sent to ECM.

Harness or connectors
(The sensor circuit is open or shorted)

Power steering pressure sensor
SEF058Y

DTC P0550 PSP SENSOR EC-1141
[VK45DE]
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Revision: 2006 July 2007 FX35/FX45
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.
Diagnostic ProcedureNBS004A1
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-819, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
12 R/G Power steering pressure
sensor [Engine is running]

Steering wheel: Being turned
0.5 - 4.5V
[Engine is running]

Steering wheel: Not being turned 0.4 - 0.8V
67 B/W Sensor ground [Engine is running]

Warm-up condition

Idle speed Approximately 0V
68 SB Sensor power supply
(Power steering pressure
sensor) [Ignition switch: ON]
Approximately 5V
PBIB2195E

DTC P0550 PSP SENSOR EC-1143
[VK45DE]
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Revision: 2006 July 2007 FX35/FX45
6. CHECK PSP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 12 and PSP sensor terminal 2. Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E306, F46

Harness for open or short between power steering pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK PSP SENSOR
Refer to EC-1143, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace PSP sensor.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-812, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component InspectionNBS004A2
POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle.
3. Check voltage between ECM terminal 12 and ground under the following conditions.
Removal and InstallationNBS004A3
POWER STEERING PRESSURE SENSOR
Refer to PS-41, "HYDRAULIC LINE" .
Continuity should exist.
Condition Voltage
Steering wheel: Being turned 0.5 - 4.5V
Steering wheel: Not being turned 0.4 - 0.8V
MBIB0126E

EC-1144
[VK45DE]
DTC P0603 ECM POWER SUPPLY
Revision: 2006 July 2007 FX35/FX45
DTC P0603 ECM POWER SUPPLYPFP:23710
Component DescriptionNBS004A8
Battery voltage is supplied to the ECM even when the ignition switch
is turned OFF for the ECM memory function of the DTC memory, the
air-fuel ratio feedback compensation value memory, the idle air vol-
ume learning value memory, etc.
On Board Diagnosis LogicNBS004A9
DTC Confirmation ProcedureNBS004AA
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. Turn ignition switch OFF, wait at least 10 seconds, and then turn ON.
5. Repeat steps 3 and 4 for four times.
6. If 1st trip DTC is detected, go to EC-1146, "
Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB1164E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0603
0603 ECM power supply cir-
cuit ECM back-up RAM system does not function
properly.

Harness or connectors
[ECM power supply (back-up) circuit is
open or shorted.]

ECM
SEF058Y

EC-1148
[VK45DE]
DTC P0605 ECM
Revision: 2006 July 2007 FX35/FX45
DTC P0605 ECMPFP:23710
Component DescriptionNBS004A4
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The ECM controls the engine.
On Board Diagnosis LogicNBS004A5
This self-diagnosis has one or two trip detection logic.
FAIL-SAFE MODE
ECM enters fail-safe mode when the malfunction A is detected.
DTC Confirmation ProcedureNBS004A6
Perform PROCEDURE FOR MALFUNCTION A first. If the 1st trip DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION B. If there is no malfunction on PROCEDURE FOR MALFUNCTION
B, perform PROCEDURE FOR MALFUNCTION C.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. If 1st trip DTC is detected, go to EC-1149, "
Diagnostic Proce-
dure" .
With GST
Follow the procedure “With CONSULT-II” above.
PBIB1164E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0605
0605 Engine control module A) ECM calculation function is malfunctioning.

ECM
B) ECM EEP-ROM system is malfunctioning.
C) ECM self shut-off function is malfunctioning.
Detected items Engine operation condition in fail-safe mode
Malfunction A

ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5
degrees) by the return spring.

ECM deactivates ASCD operation.
SEF058Y

DTC P0643 SENSOR POWER SUPPLY EC-1151
[VK45DE]
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Revision: 2006 July 2007 FX35/FX45
DTC P0643 SENSOR POWER SUPPLYPFP:18919
On Board Diagnosis LogicNBS004DA
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureNBS004DB
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-1154, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis
name DTC detecting condition Possible cause
P0643
0643 Sensor power supply
circuit short ECM detects a voltage of power source for
sensor is excessively low or high.

Harness or connectors
(APP sensor 1 circuit is shorted.)
(EVAP control system pressure sensor is
shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
(PSP sensor circuit is shorted.)

Accelerator pedal position sensor

EVAP control system pressure sensor

Refrigerant pressure sensor

Power steering pressure sensor
Engine operation condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.
SEF058Y

DTC P0643 SENSOR POWER SUPPLY EC-1153
[VK45DE]
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Revision: 2006 July 2007 FX35/FX45
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.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
48 L 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 SB Sensor power supply
(Power steering pressure
sensor) [Ignition switch: ON]
Approximately 5V
82 B/W Sensor ground
(APP sensor 1 / ICC steer-
ing switch / ASCD 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

EC-1156
[VK45DE]
DTC P0850 PNP SWITCH
Revision: 2006 July 2007 FX35/FX45
DTC P0850 PNP SWITCHPFP:23006
Component DescriptionNBS004EW
When the selector lever position is P or N, park/neutral position (PNP) switch is ON.
ECM detects the position because the continuity of the line (the ON signal) exists.
CONSULT-II Reference Value in Data Monitor ModeNBS004EX
Specification data are reference values.
On Board Diagnosis LogicNBS004EY
DTC Confirmation ProcedureNBS004EZ
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “P/N POSI SW” in “DATA MONITOR” mode with CON- SULT-II. Then check the “P/N POSI SW” signal under the follow-
ing conditions.
If NG, go to EC-1159, "
Diagnostic Procedure" .
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Start engine and warm it up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive sec- onds.
6. If 1st trip DTC is detected, go to EC-1159, "
Diagnostic Procedure" .
MONITOR ITEM CONDITION SPECIFICATION
P/N POSI SW

Ignition switch: ON Selector lever: P or N ON
Selector lever: Except above OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0850
0850 Park/neutral position
switch The signal of the park/neutral position (PNP)
switch is not changed in the process of engine
starting and driving.

Harness or connectors
[The park/neutral position (PNP) switch
circuit is open or shorted.]

Park/neutral position (PNP) switch

Unified meter and A/C amp.

TCM
Position (Selector lever) Known-good signal
N or P position ON
Except above position OFF
SEF212Y
ENG SPEED 1,200 - 6,375 rpm
COOLAN TEMP/S More than 70 °C (158 °F)
B/FUEL SCHDL 2.0 - 31.8 msec
VHCL SPEED SE More than 64 km/h (40 MPH)
Selector lever Suitable position
SEF213Y