steering INFINITI QX4 2001 Factory User Guide

SEF452Y
Idle Air Volume LearningNBEC0642
SEF454Y
SEF455Y
DESCRIPTIONNBEC0642S01ªIdle Air Volume Learningº is an operation to learn the idle air vol-
ume that keeps each engine within the specific range. It must be
performed under any of the following conditions:
IEach time IACV-AAC valve, throttle body or ECM is replaced.
IIdle speed or ignition timing is out of specification.
PRE-CONDITIONINGNBEC0642S02Before performing ªIdle Air Volume Learningº, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
IBattery voltage: More than 12.9V (At idle)
IEngine coolant temperature: 70 - 99ÉC (158 - 210ÉF)
IPNP switch: ON
IElectric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime running light systems, if
the parking brake is applied before the engine is started the
headlamp will not illuminate.
ICooling fan motor: Not operating
ISteering wheel: Neutral (Straight-ahead position)
IVehicle speed: Stopped
ITransmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until ªFLUID
TEMP SEº in ªDATA MONITORº mode of ªA/Tº system indi-
cates less than 0.9V.
For A/T models without CONSULT-II, drive vehicle for 10 min-
utes.
OPERATION PROCEDURENBEC0642S03With CONSULT-IINBEC0642S03011. Turn ignition switch ªONº and wait at least 1 second.
2. Turn ignition switch ªOFFº and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic ªPRE-CONDITION-
INGº (previously mentioned) are in good order.
5. Turn ignition switch ªOFFº and wait at least 10 seconds.
6. Start the engine and let it idle for at least 30 seconds.
7. Select ªIDLE AIR VOL LEARNº in ªWORK SUPPORTº mode.
8. Touch ªSTARTº and wait 20 seconds.
9. Make sure that ªCMPLTº is displayed on CONSULT-II screen.
If ªINCMPº is displayed, ªIdle Air Volume Learningº will not be
carried out successfully. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed 750±50 rpm (in ªPº or ªNº position)
Ignition timing 15ɱ5É BTDC (in ªPº or ªNº position)
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BASIC SERVICE PROCEDURE
Idle Air Volume Learning
EC-57

ENGINE CONTROL COMPONENT PARTS/CONTROL
SYSTEMS APPLICATION
NBEC0034S02
ItemDIAGNOSTIC TEST MODE
WORK
SUP-
PORTSELF-DIAGNOSTIC
RESULTS
D ATA
MONI-
TORD ATA
MONI-
TOR
(SPEC)ACTIVE
TESTDTC & SRT
CONFIRMATION
DTC*1FREEZE
FRAME
DATA*2SRT
STATUSDTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor
(POS)XXXX
Crankshaft position sensor (REF) X X X
Mass air flow sensor X X X
Engine coolant temperature sen-
sorXXXXX
Heated oxygen sensor 1 (front) X X X X X
Heated oxygen sensor 2 (rear) X X X X X
Vehicle speed sensorXXXX
Throttle position sensor X X X
Fuel tank temperature sensor X X X X
EVAP control system pressure
sensorXXX
Absolute pressure sensor X X X
Intake air temperature sensor X X X
Knock sensor X
Ignition switch (start signal) X X
Closed throttle position switch X X X
Closed throttle position switch
(throttle position sensor signal)XX
Air conditioner switch X X
Park/neutral position (PNP)
switchXXX
Power steering oil pressure
switchXX
Battery voltage X X
Ambient air temperature switch X X
Load signal X X
Swirl control valve control
vacuum check switchXXX
Fuel level sensor X X X
Intake valve timing control posi-
tion sensorXXX
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
EC-82

Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
INT/A TEMP SE
[ÉC] or [ÉF]qqIThe intake air temperature determined
by the signal voltage of the intake air
temperature sensor is indicated.
EVAP SYS PRES [V]qIThe signal voltage of EVAP control sys-
tem pressure sensor is displayed.
ABSOL PRES/SE [V]qIThe signal voltage of the absolute pres-
sure sensor is displayed.
FUEL LEVEL SE [V]qIThe signal voltage of the fuel level sen-
sor is displayed.
START SIGNAL
[ON/OFF]qqIIndicates [ON/OFF] condition from the
starter signal.IAfter starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF]qqIIndicates idle position [ON/OFF] com-
puted by ECM according to the throttle
position sensor signal.
CLSD THL/P SW
[ON/OFF]qIIndicates mechanical contact [ON/OFF]
condition of the closed throttle position
switch.
AIR COND SIG
[ON/OFF]qqIIndicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
P/N POSI SW
[ON/OFF]qqIIndicates [ON/OFF] condition from the
park/neutral position (PNP) switch sig-
nal.
PW/ST SIGNAL
[ON/OFF]qqI[ON/OFF] condition of the power steer-
ing oil pressure switch determined by
the power steering oil pressure signal is
indicated.
LOAD SIGNAL
[ON/OFF]qqIIndicates [ON/OFF] condition from the
electrical load signal and/or lighting
switch.
ON ... rear defogger is operating and/or
lighting switch is on.
OFF ... rear defogger is not operating
and lighting switch is not on.
IGNITION SW
[ON/OFF]qIIndicates [ON/OFF] condition from igni-
tion switch.
SWRL CONT S/V
[ON/OFF]qIThe control condition of the swirl con-
trol valve control solenoid valve (deter-
mined by ECM according to the input
signals) is indicated.
ION ... Swirl control valve is closed.
OFF ... Swirl control valve is opened.
INJ PULSE-B1
[msec]q
IIndicates the actual fuel injection pulse
width compensated by ECM according
to the input signals.IWhen the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2
[msec]
B/FUEL SCHDL
[msec]qIªBase fuel scheduleº indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board
correction.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
EC-88

Basic InspectionNBEC0038Precaution:
Perform Basic Inspection without electrical or mechanical
loads applied;
IHeadlamp switch is OFF,
IAir conditioner switch is OFF,
IRear window defogger switch is OFF,
ISteering wheel is in the straight-ahead position, etc.
1 INSPECTION START
1. Check service records for any recent repairs that may indicate a related problem, or a current need for scheduled
maintenance.
2. Open engine hood and check the following:
IHarness connectors for improper connections
IVacuum hoses for splits, kinks and improper connections
IWiring for improper connections, pinches and cuts
IAir cleaner clogging
IHoses and ducts for leaks
SEF983U
©GO TO 2.
2 CHECK THROTTLE OPENER OPERATION-I
Confirm that there is a clearance between throttle drum and stopper.
SEF950Y
OK or NG
OK©GO TO 4.
NG©GO TO 3.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Basic Inspection
EC-101

SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Engine
controlCrankshaft position sensor (REF)
circuit
22EC-510
Crankshaft position sensor (POS)
circuitEC-334, 517
Camshaft position sensor
(PHASE) circuit3EC-342
Mass air flow sensor circuit 1
122
222 2EC-150
Heated oxygen sensor 1 (front)
circuit
3EC-192
Engine coolant temperature sen-
sor circuit1 3 3 EC-169, 187
Throttle position sensor circuit 2 2 EC-174
Incorrect throttle position sensor
adjustment3 1 1 1 1 1 1 1 EC-101
Vehicle speed sensor circuit 2 3 3
3EC-417
Knock sensor circuit 2 EC-328
ECM 2233333 3 33EC-444, 117
Start signal circuit 2 EC-621
Park/Neutral position switch circuit 3 3
333 EC-604
Power steering oil pressure switch
circuit2 EC-634
Electrical load signal circuitEC-644
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Matrix Chart (Cont'd)
EC-119

MONITOR ITEM CONDITION SPECIFICATION
VHCL SPEED SEITurn drive wheels and compare speedometer indication with the CON-
SULT-II valueAlmost the same speed as
the CONSULT-II value
BATTERY VOLTIIgnition switch: ON (Engine stopped) 11 - 14V
THRTL POS SENIEngine: After warming up, idle
the engineThrottle valve: fully closed 0.15 - 0.85V
IEngine: After warming up
IIgnition switch: ON
(Engine stopped)Throttle valve: fully opened 3.5 - 4.7V
START SIGNALIIgnition switch: ON,START,ON OFF,ON,OFF
CLSD THL POS
CLSD THL/P SWIEngine: After warming up, idle
the engineThrottle valve: Idle position ON
Throttle valve: Slightly open OFF
AIR COND SIGIEngine: After warming up, idle
the engineAir conditioner switch: ªOFFº OFF
Air conditioner switch: ªONº
(Compressor operates.)ON
P/N POSI SWIIgnition switch: ONShift lever: ªPº or ªNº ON
Except above OFF
PW/ST SIGNALIEngine: After warming up, idle
the engineSteering wheel in neutral position
(forward direction)OFF
The steering wheel is turned ON
IGNITION SWIIgnition switch: ON,OFF,ON ON,OFF,ON
INJ PULSE-B2
INJ PULSE-B1IEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 2.4 - 3.2 msec
2,000 rpm 1.9 - 2.8 msec
B/FUEL SCHDLIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 2.0 - 3.2 msec
2,000 rpm 1.4 - 2.6 msec
IGN TIMINGIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 15ɱ5É BTDC
2,000 rpm More than 25É BTDC
IACV-AAC/VIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 2 - 10 step
2,000 rpm Ð
PURG VOL C/VIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 0 %
2,000 rpm Ð
A/F ALPHA-B2
A/F ALPHA-B1IEngine: After warming upMaintaining engine speed at 2,000
rpm54 - 155%
EVAP SYS PRESIIgnition switch: ON Approx. 3.4V
AIR COND RLYIAir conditioner switch: OFF,ON OFF,ON
FUEL PUMP RLYIIgnition switch is turned to ON (Operates for 5 seconds)
IEngine running and crankingON
Except as shown above OFF
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
CONSULT-II Reference Value in Data Monitor Mode (Cont'd)
EC-123

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
42 B/Y Start signal[Ignition switch ªONº]Approximately 0V
[Ignition switch ªSTARTº]9 - 12V
43 R Ignition switch[Ignition switch ªOFFº]0V
[Ignition switch ªONº]BATTERY VOLTAGE
(11 - 14V)
44 L PNP switch[Ignition switch ªONº]
IGear position is ªPº or ªNº.Approximately 0V
[Ignition switch ªONº]
IExcept the above gear positionBATTERY VOLTAGE
(11 - 14V)
45 B/RAir conditioner switch
signal[Engine is running]
IBoth A/C switch and blower switch are ªONº.Approximately 0V
[Engine is running]
IA/C switch is ªOFFº.Approximately 5V
47 R/BPower steering oil
pressure switch[Engine is running]
ISteering wheel is being turned.0 - 1.0V
[Engine is running]
ISteering wheel is not being turned.Approximately 5V
48 B ECM ground[Engine is running]
IIdle speedEngine ground
51 BR A/C cut signal[Engine is running]
IAir conditioner is operating.0 - 0.5V
52 PU Electrical load signal[Engine is running]
IRear window defogger: ON
IHi-beam headlamp: ONBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
IElectrical load: OFF0V
55 W/BSwirl control valve con-
trol vacuum check
switch[Engine is running]
IIdle speed
IEngine coolant temperature is between 15 to
50ÉC (59 to 122ÉF).Approximately 5V
[Engine is running]
IIdle speed
IEngine coolant temperature is above 55ÉC
(131ÉF).0 - 1.0V
56 OR/LThrottle position switch
(Closed position)[Engine is running]
IAccelerator pedal fully releasedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
IAccelerator pedal depressedApproximately 0V
57 B ECM ground[Engine is running]
IIdle speedEngine ground
58 B/P Sensors' ground[Engine is running]
IWarm-up condition
IIdle speedApproximately 0V
59 BFuel level sensor
ground[Engine is running]
IIdle speedApproximately 0V
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
ECM Terminals and Reference Value (Cont'd)
EC-131

DescriptionNBEC0717The specification (SP) value indicates the tolerance of the value that is displayed in ªDATA MONITOR (SPEC)º
mode of CONSULT-II during normal operation of the Engine Control System. When the value in ªDATA MONI-
TOR (SPEC)º mode is within the SP value, the Engine Control System is confirmed OK. When the value in
ªDATA MONITOR (SPEC)º mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
IB/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)
IA/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
IMAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionNBEC0718IVehicle driven distance: More than 5,000 km (3,100 miles)
IBarometric pressure: 101.3 kPa (760.0 mmHg, 29.92 inHg)±3 kPa (22.5 mmHg, 0.89 inHg)
IAtmospheric temperature: 20 - 30ÉC (68 - 86ÉF)
IEngine coolant temperature: 75 - 95ÉC (167 - 203ÉF)
ITransmission: Warmed-up*1
IElectrical load: Not applied*2
IEngine speed: Idle
*1: For A/T models, after the engine is warmed up to normal operating temperature, drive vehicle until ªFLUID
TEMP SEº (A/T fluid temperature sensor signal) indicates less than 0.9V.
*2: Rear window defogger switch, air conditioner switch, lighting switch are ªOFFº. Cooling fans are not oper-
ating. Steering wheel is straight ahead.
SEF601Z
Inspection ProcedureNBEC0719NOTE:
Perform ªDATA MONITOR (SPEC)º mode in maximum scale dis-
play.
1. Perform ªBasic Inspectionº, EC-101.
2. Confirm that the testing conditions indicated above are met.
3. Select ªB/FUEL SCHDLº, ªA/F ALPHA-B1º, ªA/F ALPHA-B2º
and ªMAS A/F SE-B1º in ªDATA MONITOR (SPEC)º mode with
CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to ªDiagnostic Procedureº, EC-137.
TROUBLE DIAGNOSIS Ð SPECIFICATION VALUE
Description
EC-136

DescriptionNBEC0249SYSTEM DESCRIPTIONNBEC0249S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed (POS signal)
Idle air
controlIACV-AAC valve Crankshaft position sensor (REF) Engine speed (REF signal)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
Park/neutral position (PNP) switch Park/neutral position
Air conditioner switch Air conditioner operation
Power steering oil pressure switch Power steering load signal
Battery Battery voltage
Vehicle speed sensor Vehicle speed
Ambient air temperature switch Ambient air temperature
Intake air temperature sensor Intake air temperature
Absolute pressure sensor Ambient barometic pressure
This system automatically controls engine idle speed to a specified
level. Idle speed is controlled through fine adjustment of the
amount of air which by-passes the throttle valve via IACV-AAC
valve. The IACV-AAC valve changes the opening of the air by-pass
passage to control the amount of auxiliary air. This valve is actu-
ated by a step motor built into the valve, which moves the valve in
the axial direction in steps corresponding to the ECM output sig-
nals. One step of IACV-AAC valve movement causes the respec-
tive opening of the air by-pass passage. (i.e. when the step
advances, the opening is enlarged.) The opening of the 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 then controls the step
position of the IACV-AAC valve so that engine speed coincides with
the target value memorized in ECM. The target engine speed is the
lowest speed at which the engine can operate steadily. The opti-
mum value stored in the ECM is determined by takig into consid-
eration various engine conditions, such as during warm up,
deceleration, and engine load (air conditioner, power steering and
cooling fan operation).
SEF765P
COMPONENT DESCRIPTIONNBEC0249S02IACV-AAC ValveNBEC0249S0201The IACV-AAC valve is operated by a step motor for centralized
control of auxiliary air supply. This motor has four winding phases
and is actuated by the output signals of ECM which turns ON and
OFF two windings each in seqeunce. Each time the IACV-AAC
valve opens or closes to change tha auxiliary air quantity, the ECM
sends a pulse signal to the step motor. When no change in the
auxiliary air quantity is needed, the ECM does not issue the pulse
signal. A certain voltage signal is issued so that the valve remains
at that particular opening.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
Description
EC-422

CONSULT-II Reference Value in Data Monitor
Mode
NBEC0250Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
IACV-AAC/VIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: ªNº
INo-loadIdle 14 - 20 step
2,000 rpm Ð
ECM Terminals and Reference ValueNBEC0670Specification 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)
6
7
8
17PU/G
GY
Y
GY/LIACV-AAC valve[Engine is running]
IIdle speed0.1 - 14V
On Board Diagnosis LogicNBEC0252Malfunction is detected when
(Malfunction A)the IACV-AAC valve does not operate properly,
(Malfunction B)the IACV-AAC valve does not operate properly.
Possible CauseNBEC0515MALFUNCTION ANBEC0515S01IHarness or connectors
(The IACV-AAC valve circuit is open.)
IIACV-AAC valve
MALFUNCTION BNBEC0515S02IHarness or connectors
(The IACV-AAC valve circuit is shorted.)
IAir control valve (Power steering)
IIACV-AAC valve
DTC Confirmation ProcedureNBEC0253NOTE:
IIf ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at least
10 seconds before conducting the next test.
IPerform ªPROCEDURE FOR MALFUNCTION Aº first. If 1st
trip DTC cannot be confirmed, perform ªPROCEDURE
FOR MALFUNCTION Bº.
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DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
CONSULT-II Reference Value in Data Monitor Mode
EC-423