2007 INFINITI FX35 engine

DTC P0507 ISC SYSTEM EC-469
[VQ35DE]
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Revision: 2006 July 2007 FX35/FX45
DTC P0507 ISC SYSTEMPFP:23781
DescriptionNBS003SU
NOTE:
If DTC P0507 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicNBS003SV
DTC Confirmation ProcedureNBS003SW
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.

If the target idle speed is out of the specified value, perform, EC-83, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-675,
"SERVICE DATA AND SPECIFICATIONS (SDS)" .
TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

Always perform the test at a temperature above −10 °C (14 °F).
WITH CONSULT-II
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON again and select “DATA MONITOR” mode with CONSULT-II.
5. Start engine and run it for at least 1 minute at idle speed.
6. If 1st trip DTC is detected, go to EC-470, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0507
0507 Idle speed control sys-
tem (ISC) RPM higher
than expected The idle speed is more than the target idle
speed by 200 rpm or more.

Electric throttle control actuator

Intake air leak

PCV system
SEF174Y

EC-470
[VQ35DE]
DTC P0507 ISC SYSTEM
Revision: 2006 July 2007 FX35/FX45
Diagnostic ProcedureNBS003SX
1. CHECK PCV HOSE CONNECTION
Confirm that PCV hose is connected correctly.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK INTAKE AIR LEAK
1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Discover air leak location and repair.
3. REPLACE ECM
1. Stop engine.
2. Replace ECM.
3. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to BL-207, "
ECM Re-Communicating Function" .
4. Perform EC-82, "
VIN Registration" .
5. Perform EC-83, "
Accelerator Pedal Released Position Learning" .
6. Perform EC-83, "
Throttle Valve Closed Position Learning" .
7. Perform EC-83, "
Idle Air Volume Learning" .
>> INSPECTION END

DTC P0550 PSP SENSOR EC-471
[VQ35DE]
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Revision: 2006 July 2007 FX35/FX45
DTC P0550 PSP SENSORPFP:49763
Component DescriptionNBS003SY
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 ModeNBS003SZ
Specification data are reference values.
On Board Diagnosis LogicNBS003T0
The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P0550 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.
Refer to EC-483, "
DTC P0643 SENSOR POWER SUPPLY" .
DTC Confirmation ProcedureNBS003T1
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-473, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB1579E
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
(Power steering pressure sensor circuit
is open or shorted)

Power steering pressure sensor
SEF058Y

DTC P0550 PSP SENSOR EC-473
[VQ35DE]
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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 ProcedureNBS003T3
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-153, "
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 BR Sensor power supply
(Power steering pressure
sensor) [Ignition switch: ON]
Approximately 5V
PBIB2625E

DTC P0550 PSP SENSOR EC-475
[VQ35DE]
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Revision: 2006 July 2007 FX35/FX45
6. CHECK INTERMITTENT INCIDENT
Refer to EC-147, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component InspectionNBS003T4
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 InstallationNBS003T5
POWER STEERING PRESSURE SENSOR
Refer to PS-41, "HYDRAULIC LINE" .
Condition Voltage
Steering wheel: Being turned 0.5 - 4.5V
Steering wheel: Not being turned 0.4 - 0.8V
MBIB0126E

EC-476
[VQ35DE]
DTC P0603 ECM POWER SUPPLY
Revision: 2006 July 2007 FX35/FX45
DTC P0603 ECM POWER SUPPLYPFP:23710
Component DescriptionNBS003TI
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 LogicNBS003TJ
DTC Confirmation ProcedureNBS003TK
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-478, "
Diagnostic Procedure"
.
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-480
[VQ35DE]
DTC P0605 ECM
Revision: 2006 July 2007 FX35/FX45
DTC P0605 ECMPFP:23710
Component DescriptionNBS003T6
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 LogicNBS003T7
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 ProcedureNBS003T8
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-481, "
Diagnostic Procedure"
.
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 ICC operation.

ECM deactivates ASCD operation.
SEF058Y

DTC P0643 SENSOR POWER SUPPLY EC-483
[VQ35DE]
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Revision: 2006 July 2007 FX35/FX45
DTC P0643 SENSOR POWER SUPPLYPFP:18919
On Board Diagnosis LogicNBS003UZ
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 ProcedureNBS003V0
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 8V 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-486, "
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.)
(PSP sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
(EVAP control system pressure sensor circuit
is shorted.)

Accelerator pedal position sensor
(APP sensor 1)

EVAP control system pressure sensor

Power steering pressure sensor

Refrigerant 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