vin INFINITI QX4 2001 Factory Service Manual

ECM Terminals and Reference ValueNBEC0678Specification 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)
1 L/YEVAP canister purge
volume control sole-
noid valve[Engine is running]
IIdle speedBATTERY VOLTAGE
(11 - 14V)
SEF994U
[Engine is running]
IEngine speed is about 2,000 rpm (More than 100
seconds after starting engine).BATTERY VOLTAGE
(11 - 14V)
SEF995U
On Board Diagnosis LogicNBEC0322Malfunction is detected when the canister purge flow is detected
during the specified driving conditions, even when EVAP canister
purge volume control solenoid valve is completely closed.
Possible CauseNBEC0588IEVAP control system pressure sensor
IEVAP canister purge volume control solenoid valve (The valve
is stuck open.)
IEVAP canister vent control valve
IEVAP canister
IHoses
(Hoses are connected incorrectly or clogged.)
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
ECM Terminals and Reference Value
EC-542

SEF032W
SEF143S
Component DescriptionNBEC0326The EVAP canister vent control valve is located on the EVAP can-
ister and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is ener-
gized. A plunger will then move to seal the canister vent. The abil-
ity to seal the vent is necessary for the on board diagnosis of other
evaporative emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the
evaporative emission control system is depressurized and allows
ªEVAP Control System (Small Leak)º diagnosis.
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0327Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/VIIgnition switch: ON OFF
ECM Terminals and Reference ValueNBEC0679Specification 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)
40 G/YEVAP canister vent
control valve[Ignition switch ªONº]BATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNBEC0329Malfunction is detected when EVAP canister vent control valve
remains closed under specified driving conditions.
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DTC P1446 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (CLOSE)
Component Description
EC-553

3 CHECK PURGE FLOW
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP service port and
install vacuum gauge.
SEF983Y
4. Start engine and let it idle for at least 80 seconds.
5. Check vacuum gauge indication when revving engine up to 2,000 rpm.
Vacuum should exist.
6. Release the accelerator pedal fully and let idle.
Vacuum should not exist.
OK or NG
OK©GO TO 7.
NG©GO TO 4.
4 CHECK EVAP PURGE LINE
1. Turn ignition switch ªOFFº.
2. Check EVAP purge line for improper connection or disconnection.
Refer to ªEVAPORATIVE EMISSION LINE DRAWINGº, EC-36.
OK or NG
OK (With CONSULT-II)©GO TO 5.
OK (Without CONSULT-
II)©GO TO 6.
NG©Repair it.
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DTC P1447 EVAPORATIVE EMISSION (EVAP) CONTROL SYSTEM PURGE
FLOW MONITORING
Diagnostic Procedure (Cont'd)
EC-565

SEF032W
SEF143S
Component DescriptionNBEC0338NOTE:
If DTC P1448 is displayed with P0440, perform trouble diagno-
sis for DTC P1448 first.
The EVAP canister vent control valve is located on the EVAP can-
ister and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is ener-
gized. A plunger will then move to seal the canister vent. The abil-
ity to seal the vent is necessary for the on board diagnosis of other
evaporative emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the
evaporative emission control system is depressurized and allows
ªEVAP Control System (Small Leak)º diagnosis.
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0339Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/VIIgnition switch: ON OFF
ECM Terminals and Reference ValueNBEC0680Specification 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)
40 G/YEVAP canister vent
control valve[Ignition switch ªONº]BATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNBEC0341Malfunction is detected when EVAP canister vent control valve
remains opened under specified driving conditions.
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DTC P1448 EVAPORATIVE EMISSION (EVAP) CANISTER VENT CONTROL
VALVE (OPEN)
Component Description
EC-573

AEC877A
Component DescriptionNBEC0367When the gear position is ªPº (A/T models only) or ªNº, park/neutral
position (PNP) switch is ªONº.
ECM detects the position because the continuity of the line (the
ªONº signal) exists.
For A/T models, the park/neutral position (PNP) switch assembly
also includes a transmission range switch to detect selector lever
position.
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0368Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
P/N POSI SWIIgnition switch: ONShift lever: ªPº or ªNº ON
Except above OFF
ECM Terminals and Reference ValueNBEC0683Specification 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)
44 L PNP switch[Ignition switch ªONº]
IGear position is ªPº or ªNº (A/T models).Approximately 0V
[Ignition switch ªONº]
IExcept the above gear positionBATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNBEC0370Malfunction is detected when the signal of the park/neutral position
(PNP) switch is not changed in the process of engine starting and
driving.
Possible CauseNBEC0595IHarness or connectors
[The park/neutral position (PNP) switch circuit is open or
shorted.]
IPark/neutral position (PNP) switch
DTC P1706 PARK/NEUTRAL POSITION (PNP) SWITCH
Component Description
EC-604

System DescriptionNBEC0392
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed (POS signal)
Fuel pump
controlFuel pump relay Crankshaft position sensor (REF) Engine speed (REF signal)
Ignition switch Start signal
The ECM activates the fuel pump for several seconds after the ignition switch is turned on to improve engine
startability. If the ECM receives a 120É signal from the crankshaft position sensor (REF), it knows that the
engine is rotating, and causes the pump to operate. If the 120É signal is not received when the ignition switch
is on, the engine stalls. The ECM stops pump operation and prevents battery discharging, thereby improving
safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn
controls the fuel pump.
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown aboveStops.
SEF018S
Component DescriptionNBEC0393The fuel pump with a fuel damper is an in-tank type (the pump and
damper are located in the fuel tank).
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0394Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FUEL PUMP RLYIIgnition switch is turned to ON. (Operates for 1 second.)
IEngine running and crankingON
Except as shown above OFF
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FUEL PUMP
System Description
EC-625

CEL083
InspectionNBEL0007FUSENBEL0007S01IIf fuse is blown, be sure to eliminate cause of problem
before installing new fuse.
IUse fuse of specified rating. Never use fuse of more than
specified rating.
IDo not partially install fuse; always insert it into fuse
holder properly.
IRemove fuse for ªELECTRICAL PARTS (BAT)º if vehicle is
not used for a long period of time.
MEL944F
FUSIBLE LINKNBEL0007S02A melted fusible link can be detected either by visual inspection or
by feeling with finger tip. If its condition is questionable, use circuit
tester or test lamp.
CAUTION:
IIf fusible link should melt, it is possible that critical circuit
(power supply or large current carrying circuit) is shorted.
In such a case, carefully check and eliminate cause of
problem.
INever wrap outside of fusible link with vinyl tape. Impor-
tant: Never let fusible link touch any other wiring harness,
vinyl or rubber parts.
SEL109W
CIRCUIT BREAKER (PTC THERMISTOR TYPE)NBEL0007S03The PTC thermister generates heat in response to current flow.
The temperature (and resistance) of the thermister element varies
with current flow. Excessive current flow will cause the element's
temperature to rise. When the temperature reaches a specified
level, the electrical resistance will rise sharply to control the circuit
current.
Reduced current flow will cause the element to cool. Resistance
falls accordingly and normal circuit current flow is allowed to
resume.
POWER SUPPLY ROUTING
Inspection
EL-16

MEL304D
ReplacementNBEL0010For removal and installation of spiral cable, refer to RS-18,
ªInstallation Ð Air Bag Module and Spiral Cableº.
IEach switch can be replaced without removing combination
switch base.
MEL326G
ITo remove combination switch base, remove base attaching
screw.
SEL151V
IBefore installing the steering wheel, align the steering wheel
guide pins with the screws which secure the combination
switch as shown in the left figure.
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COMBINATION SWITCH
Replacement
EL-29

Trouble DiagnosesNBEL0189WARNING:
IThe xenon headlamp has a high-tension current generating area. Be extremely careful when remov-
ing and installing. Be certain to disconnect the battery negative cable prior to removing or install-
ing.
IWhen the xenon headlamp is lit, do not touch the harness (covered with red or amber insulation),
bulb itself or the bulb socket with your bare hands.
INever service a xenon headlamp with wet hands.
IWhen checking body side harness with a circuit tester, be certain to disconnect the harness con-
nector from the xenon headlamp.
IWhen the xenon headlamp is lit, the xenon bulb must be installed in the headlamp housing. (Never
turn on xenon headlamp, if the bulb is out of the headlamp housing.)
CAUTION:
Make sure to install the bulb securely; if the xenon bulb is improperly installed in its socket, high-ten-
sion current leaks occur. This may lead to a melted bulb and/or bulb socket.
Symptom Possible cause Repair order
Neither headlamp operates. 1. 7.5A fuse
2. Headlamp relay circuit
3. Lighting switch
4. Lighting switch ground circuit
5. Headlamp battery saver control
unit1. Check 7.5A fuse [No. 24, located in fuse block
(J/B)].
Verify battery positive voltage is present at terminal
7 of headlamp battery saver control unit.
2. Check between battery saver control unit and head-
lamp relays (LH and RH).
3. Check Lighting switch.
4. Check harness between lighting switch terminal 8
and ground.
5. Check headlamp battery saver control unit.
Headlamp LH (low and high beam)
does not operate, but headlamp
RH (low and high beam) does
operate.1. 15A fuse
2. Headlamp LH relay
3. Headlamp LH relay circuit1. Check 15A fuse (No. 60, located in fusible link and
fuse box). Verify battery positive voltage is present
at terminals 1 and 3 of headlamp LH relay.
2. Check headlamp LH relay.
3. Check harness between headlamp LH relay and
headlamp battery saver control unit.
Headlamp RH (low and high beam)
does not operate, but headlamp LH
(low and high beam) does operate.1. 15A fuse
2. Headlamp RH relay
3. Headlamp RH relay circuit1. Check 15A fuse (No. 59, located in fusible link and
fuse box). Verify battery positive voltage is present
at terminals 1 and 3 of headlamp RH relay.
2. Check headlamp RH relay.
3. Check harness between headlamp RH relay and
headlamp battery saver control unit.
LH high beam does not operate,
but LH low beam operates.1. Bulb
2. Headlamp LH relay
3. Open in the LH high beams cir-
cuit
4. Lighting switch
5. Lighting switch ground circuit1. Check bulb.
2. Check headlamp LH relay.
3. Check the following.
a. Harness between headlamp LH relay terminal 5 and
headlamp LH for open circuit.
b. Harness between headlamp LH and lighting switch
for open circuit.
4. Check lighting switch.
5. Check harness between lighting switch and ground.
HEADLAMP (FOR USA) Ð XENON TYPE Ð
Trouble Diagnoses
EL-40

System DescriptionNBEL0153
SEL713U
This unit displays following items:
IEarth magnetism and heading direction of vehicle.
IOutside air temperature.
ICaution for frozen road surfaces.
OUTSIDE TEMPERATURE DISPLAYNBEL0153S01Push the switch when the ignition key is in the ªACCº or ªONº position. The outside temperature will be dis-
played in ªÉFº.
ISelecting the indication range
Push the switch to change from ªÉFº to ªÉCº.
IWhen the outside temperature drops below freezing point, ICE is displayed on the unit.
IWhen the outside temperature is between 55ÉC (130ÉF) and 70ÉC (158ÉF), the display shows 55ÉC
(130ÉF).
IWhen the outside temperature is lower than þ30ÉC (þ20ÉF) or higher than 70ÉC (158ÉF), the display shows
only ª---º though it is operating. This is not a problem.
IThe indicated temperature on the thermometer is not readily affected by engine heat. It changes only when
one of the following conditions is present.
a) The temperature detected by the ambient air temperature sensor is lower than the indicated temperature
on the thermometer.
b) The difference in temperature detected during a period of 40 seconds is less than 1ÉC (1.8ÉF) when vehicle
speed has been greater than 24 km/h (15 MPH) for more than 100 seconds.
(This is to prevent the indicated temperature from being affected by engine heat or cooling fan operation
during low-speed driving.)
c) The ignition key has been turned to the ªOFFº position for more than 4 hours. (The engine is cold.)
DIRECTION DISPLAYNBEL0153S02Push the switch when the ignition key is in the ªACCº or ªONº position. The direction will be displayed.
COMPASS AND THERMOMETER
System Description
EL-110