vin INFINITI QX4 2001 Factory Service Manual

SEF018S
Component Description=NBEC0622The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal
to the ECM.
It consists of two parts, one is mechanical float and the other side
is variable resistor. Fuel level sensor output voltage changes
depending on the movement of the fuel mechanical float.
On Board Diagnostic LogicNBEC0623Driving long distances naturally affect fuel gauge level.
This diagnosis detects the fuel gauge malfunction of the gauge not
moving even after a long distance has been driven.
Malfunction is detected when the output signal of the fuel level
sensor does not change within the specified range even though the
vehicle has been driven a long distance.
Possible CauseNBEC0624IHarness or connectors
(The level sensor circuit is open or shorted.)
IFuel level sensor
Overall Function CheckNBEC0625Use this procedure to check the overall function of the fuel level
sensor function. During this check, a 1st trip DTC might not be
confirmed.
WARNING:
When performing following procedure, be sure to observe the
handling of the fuel. Refer to FE-5, ªFuel Tankº.
TESTING CONDITION:
Before starting overall function check, preparation of draining
fuel and refilling fuel is required.
SEF195Y
WITH CONSULT-IINBEC0625S01NOTE:
Start from step 11, if it is possible to confirm that the fuel
cannot be drained by 30(7-7/8 US gal, 6-5/8 Imp gal) in
advance.
1) Prepare a fuel container and a spare hose.
2) Release fuel pressure from fuel line, refer to ªFuel Pressure
Releaseº, EC-39.
3) Remove the fuel feed hose on the fuel level sensor unit.
4) Connect a spare fuel hose where the fuel feed hose was
removed.
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DTC P0461 FUEL LEVEL SENSOR FUNCTION
Component Description
EC-411

Possible CauseNBEC0514IHarness or connector
(The vehicle speed sensor circuit is open or shorted.)
IVehicle speed sensor
DTC Confirmation ProcedureNBEC0245CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
TESTING CONDITION:
Steps 1 and 2 may be conducted with the drive wheels lifted
in the shop or by driving the vehicle. If a road test is expected
to be easier, it is unnecessary to lift the vehicle.
SEF196Y
WITH CONSULT-IINBEC0245S011) Start engine (TCS switch ªOFFº).
2) Read ªVHCL SPEED SEº in ªDATA MONITORº mode with
CONSULT-II. The vehicle speed on CONSULT-II should
exceed 10 km/h (6 MPH) when rotating wheels with suitable
gear position.
If NG, go to ªDiagnostic Procedureº, EC-421.
If OK, go to following step.
3) Select ªDATA MONITORº mode with CONSULT-II.
4) Warm engine up to normal operating temperature.
5) Maintain the following conditions for at least 10 consecutive
seconds.
ENG SPEED 1,800 - 6,000 rpm
COOLAN TEMP/S More than 70ÉC (158ÉF)
B/FUEL SCHDL 5.5 - 14.0 msec
Selector lever Suitable position
PW/ST SIGNAL OFF
6) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-421.
Overall Function CheckNBEC0246Use this procedure to check the overall function of the vehicle
speed sensor circuit. During this check, a 1st trip DTC might not
be confirmed.
WITH GSTNBEC0246S011) Lift up drive wheels.
2) Start engine.
3) Read vehicle speed sensor signal in ªMODE 1º with GST.
The vehicle speed sensor on GST should be able to exceed
DTC P0500 VEHICLE SPEED SENSOR (VSS)
Possible Cause
EC-418

SEF197Y
SEF198Y
DTC Confirmation ProcedureNBEC0260CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
WITH CONSULT-IINBEC0260S011) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº, wait at least 10 seconds and then
start engine.
3) Select ªCLSD THL/P SWº in ªDATA MONITORº mode.
If ªCLSD THL/P SWº is not available, go to step 5.
4) Check the signal under the following conditions.
Condition Signal indication
Throttle valve: Idle position ON
Throttle valve: Slightly open OFF
If the result is NG, go to ªDiagnostic Procedureº, EC-435.
If OK, go to following step.
5) Select ªDATA MONITORº mode with CONSULT-II.
6) Drive the vehicle for at least 5 consecutive seconds under the
following condition.
THRTL POS SEN More than 2.5V
VHCL SPEED SE More than 5 km/h (3 MPH)
Selector lever Suitable position
Driving locationDriving vehicle uphill (Increased engine load)
will help maintain the driving conditions
required for this test.
7) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-435.
SEF345X
Overall Function CheckNBEC0261Use this procedure to check the overall function of the closed
throttle position switch circuit. During this check, a 1st trip DTC
might not be confirmed.
WITH GSTNBEC0261S011) Start engine and warm it up to normal operating temperature.
2) Check the voltage between ECM terminal 56 (Closed throttle
position switch signal) and ground under the following condi-
tions.
At idle: Battery voltage
DTC P0510 CLOSED THROTTLE POSITION SWITCH
DTC Confirmation Procedure
EC-432

DescriptionNBEC0691SYSTEM DESCRIPTIONNBEC0691S01
Sensor Input signal to ECM function ECM Actuator
Crankshaft positon sensor (POS) Engine speed (POS)
Intake valve
timing con-
trolIntake valve timing control sole-
noid valve Crankshaft position sensor (REF) Engine speed (REF)
Camshaft position sensor Engine speed
Engine coolant temperature sensor Engine coolant temperature
Vehicle speed sensor Vehicle speed
JEF349Z
This mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake
valve.
The ECM receives signals such as crankshaft position, camshaft position, engine speed, and engine coolant
temperature. Then, the ECM sends ON/OFF pulse duty signals to the camshaft timing control valve depend-
ing on driving status. This makes it possible to control the shut/open timing of the intake valve to increase
engine torque in low/mid speed range and output in high-speed range.
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0692Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
INT/V TIM (B1)
INT/V TIM (B2)IEngine: After warming up
IShift lever ªNº
IQuickly depressed accelerator
pedal
INo-loadIdle 0É CA
2,000 rpm Approximately 12 - 18É CA
INT/V SOL (B1)
INT/V SOL (B2)IEngine: After warming up
IShift lever ªNº
IQuickly depressed accelerator
pedal
INo-loadIdle 0%
2,000 rpm Approximately 40%
DTC P1110 (RIGHT, -B1), P1135 (LEFT, -B2) INTAKE VALVE TIMING CONTROL
Description
EC-446

DTC Confirmation ProcedureNBEC0696CAUTION:
Always drive at a safe speed.
NOTE:
IIf both DTC P1111(B1), P1136 (B2) or P1140 (B1), P1145
(B2) and P1110 (B1), P1135 (B2) are displayed, perform
trouble diagnosis for ªDTC P1111(B1), P1136 (B2) or
P1140 (B1), P1145 (B2)º first. (See EC-451, 482.)
IIf ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at
least 10 seconds before conducting the next test.
SEF353Z
PROCEDURE FOR MALFUNCTION ANBEC0696S01With CONSULT-IINBEC0696S01011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Maintain the following conditions for at least 10 consecutive
seconds.
ENG SPEED More than 2,000 rpm
COOLANT TEMPS More than 70ÉC (158ÉF)
Selector lever 1st position
Driving locationDriving vehicle uphill
(Increased engine load will help main-
tain the driving conditions required for
this test.)
4) Maintain the following conditions for at least 20 consecutive
seconds.
ENG SPEED Idle
COOLANT TEMPS More than 70ÉC (158ÉF)
Selector lever ªPº or ªNº position
5) If 1st trip DTC is detected, go to ªP1140, P1145 INTAKE
VALVE TIMING CONTROL POSITION SENSORº. Refer to
EC-482.
With GSTNBEC0696S0102Follow the procedure ªWith CONSULT-IIº above.
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DTC P1110 (RIGHT, -B1), P1135 (LEFT, -B2) INTAKE VALVE TIMING CONTROL
DTC Confirmation Procedure
EC-449

SEF353Z
PROCEDURE FOR MALFUNCTION B=NBEC0696S02With CONSULT-IINBEC0696S02011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Maintain the following conditions for at least 20 consecutive
seconds.
ENG SPEED2,000 - 3,000 rpm (A constant rotation
is maintained.)
COOLANT TEMPS 70 - 90ÉC (158 - 194ÉF)
Selector lever 1st or position
Driving location uphillDriving vehicle uphill
(Increased engine load will help main-
tain the driving conditions required for
this test.)
4) If 1st trip DTC is detected, go to ªP1140, P1145 INTAKE
VALVE TIMING CONTROL POSITION SENSORº. Refer to
EC-482.
With GSTNBEC0696S0202Follow the procedure ªWith CONSULT-IIº above.
DTC P1110 (RIGHT, -B1), P1135 (LEFT, -B2) INTAKE VALVE TIMING CONTROL
DTC Confirmation Procedure (Cont'd)
EC-450

DescriptionNBEC0523If DTC P1130 is displayed with P1165, first perform trouble diag-
nosis for DTC P1165, EC-493.
SYSTEM DESCRIPTIONNBEC0523S01
Sensor Input Signal to ECMECM func-
tionActuator
Throttle position sensor Throttle position
Swirl control
valve con-
trolSwirl control valve control sole-
noid valve
"Vacuum signal
Swirl control valve actuator
"
Swirl control valve Ignition switch Start signal
Crankshaft position sensor (POS) Engine speed (POS signal)
Crankshaft position sensor (REF) Engine speed (REF signal)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
This system has a swirl control valve in the intake passage of each
cylinder.
While idling and during low engine speed operation, the swirl con-
trol valve closes. Thus the velocity of the air in the intake passage
increases, promoting the vaporization of the fuel and producing a
swirl in the combustion chamber.
Because of this operation, this system tends to increase the burn-
ing speed of the gas mixture, improve fuel consumption, and
increase the stability in running conditions.
Also, except when idling and during low engine speed operation,
this system opens the swirl control valve. In this condition, this
system tends to increase power by improving intake efficiency via
reduction of intake flow resistance, intake flow.
The solenoid valve controls swirl control valve's shut/open condi-
tion. This solenoid valve is operated by the ECM.
Throttle position
sensor (Idle posi-
tion)Engine speedSwirl control valve
control solenoid
valveSwirl control valve
ON Below 3,200 rpm ON Closed
OFFLess than 3,200
rpmON Closed
More than 3,600
rpmOFF Open
When engine coolant temperature is below 10ÉC (50ÉF) and above 55ÉC (131ÉF),
swirl control valve is kept open regardless of above condition.
SEF446Z
DTC P1130 SWIRL CONTROL VALVE CONTROL SOLENOID VALVE
Description
EC-458

SEF002Z
COMPONENT DESCRIPTIONNBEC0523S02Swirl Control Valve Control Solenoid ValveNBEC0523S0201The swirl control valve control solenoid valve responds to signals
from the ECM. When the ECM sends an ON (ground) signal, the
solenoid valve is bypassed to apply intake manifold vacuum to the
swirl control valve actuator. This operation closes the swirl control
valve. When the ECM sends an OFF signal, the vacuum signal is
cut and the swirl control valve opens.
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0524Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
SWRL CONT S/VIEngine speed: IdleEngine coolant temperature is
between 15ÉC (59ÉF) to 50ÉC
(122ÉF).ON
Engine coolant temperature is
above 55ÉC (131ÉF).OFF
ECM Terminals and Reference ValueNBEC0673Specification 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.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
29 GSwirl control valve con-
trol solenoid valve[Engine is running]
IIdle speed
IEngine coolant temperature is between 15 to
50ÉC (59 to 122ÉF).0 - 1.0V
[Engine is running]
IIdle speed
IEngine coolant temperature is above 55ÉC
(131ÉF).BATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNBEC0526Malfunction is detected when
(Malfunction A)An improper voltage signal is sent to ECM through
swirl control valve control solenoid valve,
(Malfunction B)The vacuum signal is not sent to swirl control
valve under specified driving conditions, even though swirl control
valve control solenoid valve is ON,
(Malfunction C)The vacuum signal is sent to swirl control valve
even though swirl control valve control solenoid valve is OFF.
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DTC P1130 SWIRL CONTROL VALVE CONTROL SOLENOID VALVE
Description (Cont'd)
EC-459

On Board Diagnosis LogicNBEC0282HThe closed loop control has the one trip detection logic.
Malfunction is detected when the closed loop control function for
right bank does not operate even when vehicle is driving in the
specified condition, the closed loop control function for left bank
does not operate even when vehicle is driving in the specified
condition.
Possible CauseNBEC0531IThe front heated oxygen sensor circuit is open or shorted.
IHeated oxygen sensor 1 (front)
IHeated oxygen sensor 1 heater (front)
DTC Confirmation ProcedureNBEC0283CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
TESTING CONDITION:
INever raise engine speed above 3,600 rpm during the
ªDTC Confirmation Procedureº. If the engine speed limit is
exceeded, retry the procedure from step 2.
IBefore performing the following procedure, confirm that
battery voltage is more than 11V at idle.
SEF063Y
WITH CONSULT-IINBEC0283S011) Start engine and warm it up to normal operating temperature.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Hold engine speed at 2,000 rpm and check one of the follow-
ing.
IªHO2S1 (B1)/(B2)º voltage should go above 0.70V at least
once.
IªHO2S1 (B1)/(B2)º voltage should go below 0.21V at least
once.
If the check result is NG, perform ªDiagnosis Procedureº,
EC-492.
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DTC P1148 (RIGHT BANK, -B1), P1168 (LEFT BANK, -B2) CLOSED LOOP
CONTROL
On Board Diagnosis Logic
EC-491

11 CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve attached.
The weight should be less than 1.8 kg (4.0 lb).
OK or NG
OK (With CONSULT-II)©GO TO 13.
OK (Without CONSULT-
II)©GO TO 14.
NG©GO TO 12.
12 DETECT MALFUNCTIONING PART
Check the following.
IEVAP canister for damage
IEVAP hose between EVAP canister and water separator for clogging or poor connection
©Repair hose or replace EVAP canister.
13 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
With CONSULT-II
1. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
2. Start engine.
3. Perform ªPURG VOL CONT/Vº in ªACTIVE TESTº mode.
4. Touch ªQuº on CONSULT-II screen to increase ªPURG VOL CONT/Vº opening to 100.0%.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
SEF984Y
OK or NG
OK©GO TO 16.
NG©GO TO 15.
14 CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
4. Start engine and let it idle for at least 80 seconds.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
Vacuum should exist.
OK or NG
OK©GO TO 17.
NG©GO TO 15.
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DTC P1441 EVAP CONTROL SYSTEM (VERY SMALL LEAK)
Diagnostic Procedure (Cont'd)
EC-535