INFINITI FX35 2008 Service Manual

DTC P0507 ISC SYSTEMEC-411
< SERVICE INFORMATION > [VQ35DE]
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DTC P0507 ISC SYSTEM
DescriptionINFOID:0000000001326250
NOTE:
If DTC P0507 is displayed with ot
her DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified leve l through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric thrott le control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idli ng 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 t he 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 LogicINFOID:0000000001326251
DTC Confirmation ProcedureINFOID:0000000001326252
NOTE:
 If DTC Confirmation Procedure has been previously conduc ted, 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-85, "
Idle Air Volume Learning",
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-593
.
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).
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and run it for at least 1 minute at idle speed.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-411, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001326253
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.
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
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EC-412
< SERVICE INFORMATION >[VQ35DE]
DTC P0507 ISC SYSTEM
Refer to
BL-187, "ECM Re-Communicating Function".
4. Perform EC-84, "
VIN Registration".
5. Perform EC-85, "
Accelerator Pedal Released Position Learning".
6. Perform EC-85, "
Throttle Valve Closed Position Learning".
7. Perform EC-85, "
Idle Air Volume Learning".
>> INSPECTION END
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DTC P0550 PSP SENSOREC-413
< SERVICE INFORMATION > [VQ35DE]
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DTC P0550 PSP SENSOR
Component DescriptionINFOID:0000000001326254
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-III Reference Val ue in Data Monitor ModeINFOID:0000000001326255
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001326256
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-424
.
DTC Confirmation ProcedureINFOID:0000000001326257
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
1. Start engine and let it idle for at least 5 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-415, "
Diagnosis Procedure".
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 pressure
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
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EC-414
< SERVICE INFORMATION >[VQ35DE]
DTC P0550 PSP SENSOR
Wiring Diagram
INFOID:0000000001326258
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring in put/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
TBWM0302E
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DTC P0550 PSP SENSOREC-415
< SERVICE INFORMATION > [VQ35DE]
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Diagnosis ProcedureINFOID:0000000001326259
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 POWER STEERING PRESSURE (P SP) SENSOR POWER SUPPLY CIRCUIT
1. Disconnect power steering pressure (PSP) sensor harness con- nector.
2. Turn ignition switch ON.
TER-
MI-
NAL
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
PBIB1579E
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EC-416
< SERVICE INFORMATION >[VQ35DE]
DTC P0550 PSP SENSOR
3. Check voltage between PSP sensor terminal 1 and ground with
CONSULT-III or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
3.CHECK POWER STEERING PRESSURE SENSO R GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between PSP sensor terminal 3 and ECM terminal 67. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK POWER STEERING PRESSURE SENSOR INPU T 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 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK POWER STEERING PRESSURE SENSOR
Refer to EC-416, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace power steering pressure sensor.
6.CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
>> INSPECTION END
Component InspectionINFOID:0000000001326260
POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle. Voltage: Approximately 5V
PBIB0188E
Continuity should exist.
Continuity should exist.
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DTC P0550 PSP SENSOREC-417
< SERVICE INFORMATION > [VQ35DE]
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3. Check voltage between ECM terminal 12 and ground under the
following conditions.
Removal and InstallationINFOID:0000000001326261
POWER STEERING PRESSURE SENSOR
Refer to PS-37.
Condition Voltage
Steering wheel: Being turned 0.5 - 4.5V
Steering wheel: Not being turned 0.4 - 0.8V
MBIB0126E
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EC-418
< SERVICE INFORMATION >[VQ35DE]
DTC P0603 ECM POWER SUPPLY
DTC P0603 ECM POWER SUPPLY
Component DescriptionINFOID:0000000001326262
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 Diagn
osis LogicINFOID:0000000001326263
DTC Confirmation ProcedureINFOID:0000000001326264
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
1. Turn ignition switch ON and wait at least 1 second.
2. Start engine and let it idle for 1 second.
3. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
4. Repeat steps 2 and 3 for four times.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-420, "
Diagnosis Procedure".
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 (b ack-up) circuit is
open or shorted.]
ECM
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DTC P0603 ECM POWER SUPPLYEC-419
< SERVICE INFORMATION > [VQ35DE]
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Wiring DiagramINFOID:0000000001326265
Specification data are reference values
and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals wh en measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
TBWM1393E
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EC-420
< SERVICE INFORMATION >[VQ35DE]
DTC P0603 ECM POWER SUPPLY
Diagnosis Procedure
INFOID:0000000001326266
1.CHECK ECM POWER SUPPLY
1. Turn ignition switch OFF.
2. Check voltage between ECM terminal 121 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 Harness connector E211, M41
 20A fuse
 IPDM E/R harness connector E8
 Harness for open or short between ECM and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
3.CHECK INTERMITTENT INCIDENT
Refer to EC-139
.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness or connectors.
4.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Turn ignition switch ON.
2. Select “SELF DIAG RESULTS” mode with CONSULT-III.
3. Touch “ERASE”.
4. Perform DTC Confirmation Procedure.
See EC-418, "
DTC Confirmation Procedure".
5. Is the 1st trip DTC P0603 displayed again?
With GST
1. Turn ignition switch ON.
2. Select Service $04 with GST.
3. Perform DTC Confirmation Procedure.
See EC-418, "
DTC Confirmation Procedure".
4. Is the 1st trip DTC P0603 displayed again?
Ye s o r N o
Ye s > > G O T O 5 .
No >> INSPECTION END
5.REPLACE ECM
TER-
MI-
NAL
NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
121 R/W Power supply for ECM
(Back-up) [Ignition switch OFF]
BATTERY VOLTAGE
(11 - 14V)
Voltage: Battery voltage
MBIB0026E
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