Power steering system INFINITI FX35 2004 Workshop Manual

TROUBLE DIAGNOSIS
EC-115
[VQ35DE]
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Revision: 2004 November 2004 FX35/FX45FUEL T/TEMP SE
[°C] or [°F]×
The fuel temperature (determined by the
signal voltage of the fuel tank temperature
sensor) is displayed.
INT/A TEMP SE
[°C] or [°F]××

The intake air temperature (determined by
the signal voltage of the intake air tempera-
ture sensor) is indicated.
EVAP SYS PRES [V]×

The signal voltage of EVAP control system
pressure sensor is displayed.
FUEL LEVEL SE [V]×

The signal voltage of the fuel level sensor is
displayed.
START SIGNAL
[ON/OFF]××

Indicates start signal status [ON/OFF] com-
puted by the ECM according to the signals
of engine speed and battery voltage.
After starting the engine, [OFF] is dis-
played regardless of the starter sig-
nal.
CLSD THL POS
[ON/OFF]××

Indicates idle position [ON/OFF] computed
by ECM according to the accelerator pedal
position sensor signal.
AIR COND SIG
[ON/OFF]××

Indicates [ON/OFF] condition of the air con-
ditioner switch as determined by the air
conditioner signal.
P/N POSI SW
[ON/OFF]××

Indicates [ON/OFF] condition from the park/
neutral position (PNP) switch signal.
PW/ST SIGNAL
[ON/OFF]××

[ON/OFF] condition of the power steering
system (determined by the signal voltage of
the power steering pressure sensor signal)
is indicated.
LOAD SIGNAL
[ON/OFF]××

Indicates [ON/OFF] condition from the elec-
trical load signal.
ON: Rear window defogger switch is ON
and/or lighting switch is in 2nd position.
OFF: Both rear window defogger switch
and lighting switch are OFF.
SNOW MODE SW
[ON/OFF]

Indicates [ON/OFF] condition from the
snow mode switch signal.
IGNITION SW
[ON/OFF]×

Indicates [ON/OFF] condition from ignition
switch signal.
HEATER FAN SW
[ON/OFF]×

Indicates [ON/OFF] condition from the
heater fan switch signal.
BRAKE SW
[ON/OFF]

Indicates [ON/OFF] condition from the stop
lamp switch signal.
INJ PULSE-B1
[msec]×

Indicates the actual fuel injection pulse
width compensated by ECM according to
the input signals.
When the engine is stopped, a cer-
tain computed value is indicated.
INJ PULSE-B2
[msec]
IGN TIMING [BTDC]×

Indicates the ignition timing computed by
ECM according to the input signals.
When the engine is stopped, a cer-
tain value is indicated.
CAL/LD VALUE [%]

Calculated load value indicates the value of
the current air flow divided by peak air flow.
MASS AIRFLOW
[g·m/s]

Indicates the mass air flow computed by
ECM according to the signal voltage of the
mass air flow sensor. Monitored item [Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks

EC-392
[VQ35DE]
DTC P0506 ISC SYSTEM
Revision: 2004 November 2004 FX35/FX45
DTC P0506 ISC SYSTEMPFP:23781
DescriptionABS006SE
NOTE:
If DTC P0506 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 LogicABS006SF
DTC Confirmation ProcedureABS006SG
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-49, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-660,
"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-393, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0506
0506Idle speed control sys-
tem RPM lower than
expectedThe idle speed is less than the target idle
speed by 100 rpm or more.

Electric throttle control actuator

Intake air leak
SEF174Y

EC-394
[VQ35DE]
DTC P0507 ISC SYSTEM
Revision: 2004 November 2004 FX35/FX45
DTC P0507 ISC SYSTEMPFP:23781
DescriptionABS006SI
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 LogicABS006SJ
DTC Confirmation ProcedureABS006SK
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-49, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-660,
"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-395, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0507
0507Idle speed control sys-
tem RPM higher than
expectedThe idle speed is more than the target idle
speed by 200 rpm or more.

Electric throttle control actuator

Intake air leak

PCV system
SEF174Y

DTC P1229 SENSOR POWER SUPPLY
EC-489
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Revision: 2004 November 2004 FX35/FX45
DTC P1229 SENSOR POWER SUPPLYPFP:16119
On Board Diagnosis LogicABS00CHP
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 ProcedureABS00CHQ
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-491, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P1229
1229Sensor power supply
circuit shortECM 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) by the return
spring.
SEF058Y

DTC P1229 SENSOR POWER SUPPLY
EC-491
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Revision: 2004 November 2004 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 ProcedureABS00CHS
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-141, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
49 PUSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V
68 BRSensor power supply
(Power steering pressure
sensor)[Ignition switch: ON]Approximately 5V
90 L/BSensor power supply
(APP sensor 1)[Ignition switch: ON]Approximately 5V
48 LGSensor power supply
(EVAP control system pres-
sure sensor)[Ignition switch: ON]Approximately 5V
PBIB2195E

EC-492
[VQ35DE]
DTC P1229 SENSOR POWER SUPPLY
Revision: 2004 November 2004 FX35/FX45
2. CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT
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-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
3. CHECK SENSOR POWER SUPPLY CIRCUITS
Check the following.

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

ECM pin terminal.
OK or NG
OK >> GO TO 4.
NG >> Repair short to ground or short to power in harness or connectors.
4. CHECK COMPONENTS
Check the following.

Refrigerant pressure sensor (Refer to AT C - 9 0 , "COMPONENT INSPECTION" .)

Power steering pressure sensor (Refer to EC-400, "Component Inspection" .)

EVAP control system pressure sensor (Refer to EC-351, "Component Inspection" .)
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning component.
PBIB1580E
Voltage: Approximately 5V
PBIB0914E
ECM terminal Sensor terminal Reference Wiring Diagram
90 APP sensor terminal 6EC-557
49 Refrigerant pressure sensor terminal 1EC-610
91 PSP sensor terminal 1EC-397
48 EVAP control system pressure sensor terminal 3EC-354

AUTOMATIC SPEED CONTROL DEVICE (ASCD)
EC-657
[VQ35DE]
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Revision: 2004 November 2004 FX35/FX45
AUTOMATIC SPEED CONTROL DEVICE (ASCD)PFP:18930
System DescriptionABS006ZG
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/
h (25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE indicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
SET OPERATION
Press ON/OFF(MAIN)) switch. (The CRUISE indicator in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press COAST/SET switch. (Then SET indicator in combination meter illuminates.)
ACCEL OPERATION
If the ACCEL/RESUME switch is pressed during cruise control driving, increase the vehicle speed until the
switch is released or vehicle speed reaches maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.

CANCEL switch is pressed

More than 2 switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)

Brake pedal is depressed

Selector lever is changed to N, P, R position

Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed

VDC/TCS system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.

Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by depressing COAST/SET switch or ACCEL/
RESUME switch.

Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If ON/OFF(MAIN) switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled
and vehicle speed memory will be erased.
COAST OPERATION
When the COAST/SET switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed controlElectric throttle control
actuator Stop lamp switch Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switchGear position
Unified meter and A/C amp.* Vehicle speed
TCM* Powertrain revolution

EC-678
[VK45DE]
ENGINE CONTROL SYSTEM
Revision: 2004 November 2004 FX35/FX45
System ChartABS00BZ5
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This sensor is not used to control the engine system under normal conditions.
*3: This input signal is sent to the ECM through CAN communication line.
*4: This output signal is sent from the ECM through CAN communication line.Input (Sensor) ECM Function Output (Actuator)

Camshaft position sensor (PHASE)

Crankshaft position sensor (POS)

Intake valve timing control position sensor

Mass air flow sensor

Engine coolant temperature sensor

Heated oxygen sensor 1

Throttle position sensor

Accelerator pedal position sensor

Park/neutral position (PNP) switch

Intake air temperature sensor

Power steering pressure sensor

Ignition switch

Battery voltage

Knock sensor

Refrigerant pressure sensor

Stop lamp switch

ICC steering switch

ICC brake switch

ASCD steering switch

ASCD brake switch

Fuel level sensor*1 *3

EVAP control system pressure sensor

Fuel tank temperature sensor*1

Heated oxygen sensor 2*2

TCM (Transmission control module)*3

ABS actuator and electric unit (control unit)*3

ICC unit*3

Air conditioner switch*3

Wheel sensor*3

Electrical load signal*3
Fuel injection & mixture ratio control Fuel injector
Electronic ignition system Power transistor
Nissan torque demand control system

Electric throttle control actuator

Fuel injector
Fuel pump control Fuel pump relay
ICC vehicle speed control
Electric throttle control actuator
ASCD vehicle speed control
On board diagnostic system
MIL (On the instrument panel)*
4
Power valve control VIAS control solenoid valve
Intake valve timing controlIntake valve timing control solenoid
valve
Heated oxygen sensor 1 heater control Heated oxygen sensor 1 heater
Heated oxygen sensor 2 heater control Heated oxygen sensor 2 heater
EVAP canister purge flow controlEVAP canister purge volume control
solenoid valve
Air conditioning cut control
Air conditioner relay*
4
Cooling fan control
Cooling fan relay*4
ON BOARD DIAGNOSIS for EVAP system EVAP canister vent control valve

ENGINE CONTROL SYSTEM
EC-679
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Revision: 2004 November 2004 FX35/FX45
Multiport Fuel Injection (MFI) SystemABS00BZ6
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system under normal conditions.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor (POS), camshaft
position sensor (PHASE) and the mass air flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.
<Fuel increase>

During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D

High-load, high-speed operation
<Fuel decrease>

During deceleration

During high engine speed operation
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery
Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit)*
2VDC/TCS operation command
Air conditioner switch*
2Air conditioner operation
Wheel sensor*
2Vehicle speed

EC-682
[VK45DE]
ENGINE CONTROL SYSTEM
Revision: 2004 November 2004 FX35/FX45

At idle

At low battery voltage

During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Nissan Torque Demand (NTD) Control SystemABS00BZ8
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
NTD control system decides the target traction based on the accelerator operation status and the current driv-
ing condition. It then selects the engine torque target by correcting running resistance and atmospheric pres-
sure, and controlling the power-train. Using electric throttle control actuator, it achieves the engine torque
development target which corresponds linearly to the driver's accelerator operation.
Running resistance correction control compares the engine torque estimate value, measured vehicle acceler-
ation, and running resistance on a flat road, and estimates vehicle weight gain and running resistance varia-
tion caused by slopes to correct the engine torque estimate value.
Atmospheric pressure correction control compares the engine torque estimate value from the airflow rate and
the target engine torque for the target traction, and estimates variation of atmospheric pressure to correct the
target engine torque. This system achieves powerful driving without reducing engine performance in the prac-
tical speed range in mountains and high-altitude areas.
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
NTD controlElectric throttle con-
trol actuator and fuel
injector Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/Neutral position (PNP) switch Gear position
Power steering pressure sensor Power steering operation
Battery Battery voltage
TCM (CAN communication) A/T control signal
Air conditioner switch* Air conditioner operation
ABS actuator and electric unit (control unit)* VDC/TCS/ABS operation
Wheel sensor* Vehicle speed
Electrical load* Electrical load signal