2001 INFINITI QX4 Crankshaft position sensor pos

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
85 YCrankshaft position
sensor (POS)[Engine is running]
IIdle speedApproximately 2.4V
SEF057V
[Engine is running]
IEngine speed is 2,000 rpm.Approximately 2.3V
SEF058V
86 W/L Vehicle speed sensor[Engine is running]
IJack up front wheels.
IIn 1st gear position
I10 km/h (6 MPH)Approximately 2.5VSEF583X
[Engine is running]
IJack up front wheels.
IIn 2nd gear position
I30 km/h (19 MPH)Approximately 2.0V
SEF584X
89 ORIntake valve timing
control position sen-
sors (LH)[Engine is running]
IWarm-up condition
IIdle speedApproximatley 0.5VSEF351Z
[Engine is running]
IWarm-up condition
IEngine speed is 2,000 rpm.Approximatley 0.5V
SEF352Z
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
ECM Terminals and Reference Value (Cont'd)
EC-134

ICrankshaft position sensor (REF)
ICrankshaft position sensor (POS)
IMass air flow sensor
MALFUNCTION CNBEC0430S03IHarness or connectors
(The throttle position sensor circuit is open or shorted.)
IIntake air leaks
IThrottle position sensor
DTC Confirmation ProcedureNBEC0078NOTE:
IPerform ªPROCEDURE FOR MALFUNCTION Aº first. If the
1st trip DTC cannot be confirmed, perform ªPROCEDURE
FOR MALFUNCTION Bº.
If there is no problem on ªPROCEDURE FOR MALFUNC-
TION Bº, perform ªPROCEDURE FOR MALFUNCTION Cº.
IIf ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at least
10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION ANBEC0078S01CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
IBefore performing the following procedure, confirm that
battery voltage is more than 10V at idle.
IThis test 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.
SEF065Y
With CONSULT-IINBEC0078S01011) Turn ignition switch ªONº and select ªDATA MONITORº mode
with CONSULT-II.
2) Start engine and maintain the following conditions for at least
5 consecutive seconds.
Vehicle speed More than 5 km/h (3 MPH)
Selector lever Suitable position except ªPº or ªNº position
3) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-181.
With GSTNBEC0078S0102Follow the procedure ªWith CONSULT-IIº above.
DTC P0120 THROTTLE POSITION SENSOR
Possible Cause (Cont'd)
EC-176

12 CHECK MASS AIR FLOW SENSOR
1. Reconnect harness connectors disconneted.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 61 (Mass air flow sensor signal) and ground.
SEF298X
4. If the voltage is out of specification, disconnect mass air flow sensor harness connector and connect it again.
Then repeat above check.
OK or NG
OK©GO TO 13.
NG©Replace mass air flow sensor.
13 CHECK CRANKSHAFT POSITION SENSOR (POS)
1. Install all removed parts.
2. Perform ªDTC Confirmation Procedureº for DTC P0335 and P1336. Refer to EC-336, 519.
OK or NG
OK©GO TO 14.
NG©Replace crankshaft position sensor (POS).
14 CHECK CRANKSHAFT POSITION SENSOR (REF)
Perform ªDTC Confirmation Procedureº for DTC P1335. Refer to EC-511.
OK or NG
OK©GO TO 15.
NG©Replace crankshaft position sensor (REF).
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0120 THROTTLE POSITION SENSOR
Diagnostic Procedure (Cont'd)
EC-185

DescriptionNBEC0123SYSTEM DESCRIPTIONNBEC0123S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS)
Engine speedHeated
oxygen
sensor 1
heater
(front) con-
trolHeated oxygen sensor 1 heat-
ers (front)
Crankshaft position sensor (REF)
The ECM performs ON/OFF control of the heated oxygen sensor 1 heaters (front) corresponding to the engine
speed.
OPERATIONNBEC0123S02
Engine speed rpm Heated oxygen sensor 1 heaters (front)
Above 3,600 OFF
Below 3,600 ON
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0124Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 HTR (B1)
HO2S1 HTR (B2)IEngine speed: Below 3,600 rpm ON
IEngine speed: Above 3,600 rpm OFF
ECM Terminals and Reference ValueNBEC0657Specification 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)
3 L/ORHeated oxygen sensor
1 heater (front) (bank
1)[Engine is running]
IEngine speed is below 3,600 rpm.0 - 1.0V
[Engine is running]
IEngine speed is above 3,600 rpm.BATTERY VOLTAGE
(11 - 14V)
2 R/GHeated oxygen sensor
1 heater (front) (bank
2)[Engine is running]
IEngine speed is below 3,600 rpm.0 - 1.0V
[Engine is running]
IEngine speed is above 3,600 rpm.BATTERY VOLTAGE
(11 - 14V)
DTC P0135, P0155 HEATED OXYGEN SENSOR 1 HEATER (FRONT) (BANK
1)/(BANK 2)
Description
EC-240

DescriptionNBEC0162SYSTEM DESCRIPTIONNBEC0162S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS)
Engine speedHeated
oxygen
sensor 2
heater
(rear) con-
trolHeated oxygen sensor 2 heat-
ers (rear)
Crankshaft position sensor (REF)
The ECM performs ON/OFF control of the heated oxygen sensor 2 heaters (rear) corresponding to the engine
speed.
OPERATIONNBEC0162S02
Engine speed rpm Heated oxygen sensor 2 heaters (rear)
Above 3,200 OFF
Below 3,200 ON
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0163Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)IIgnition switch: ON (Engine stopped)
IEngine is running above 3,200 rpm.OFF
IEngine is running below 3,200 rpm after driving for 2 minutes at a
speed of 70 km/h (43 MPH) or more.ON
ECM Terminals and Reference ValueNBEC0662Specification 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)
5 P/BHeated oxygen sensor
2 heater (rear) (bank
1)[Engine is running]
IEngine speed is below 3,200 rpm.
IAfter driving for 2 minutes at a speed of 70 km/h
(43 MPH) or more.0 - 1.0V
[Ignition switch ªONº]
IEngine stopped
[Engine is running]
IEngine speed is above 3,200 rpm.BATTERY VOLTAGE
(11 - 14V)
4 R/WHeated oxygen sensor
2 heater (rear) (bank
2)[Engine is running]
IEngine speed is below 3,200 rpm.
IAfter driving for 2 minutes at a speed of 70 km/h
(43 MPH) or more.0 - 1.0V
[Ignition switch ªONº]
IEngine stopped
[Engine is running]
IEngine speed is above 3,200 rpm.BATTERY VOLTAGE
(11 - 14V)
DTC P0141, P0161 HEATED OXYGEN SENSOR 2 HEATER (REAR) (BANK 1)/
(BANK 2)
Description
EC-286

On Board Diagnosis LogicNBEC0182When a misfire occurs, engine speed will fluctuate. If the engine
speed fluctuates enough to cause the CKP sensor signal to vary,
ECM can determine that a misfire is occurring.
Sensor Input Signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)
On the first trip that a misfire condition occurs that can dam-
age the three way catalyst (TWC) due to overheating, the MIL
will blink.
When a misfire condition occurs, the ECM monitors the CKP
sensor signal every 200 engine revolutions for a change.
When the misfire condition decreases to a level that will not
damage the TWC, the MIL will turn off.
If another misfire condition occurs that can damage the TWC
on a second trip, the MIL will blink.
When the misfire condition decreases to a level that will not
damage the TWC, the MIL will remain on.
If another misfire condition occurs that can damage the TWC,
the MIL will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration)
For misfire conditions that will not damage the TWC (but will
affect vehicle emissions), the MIL will only light when the mis-
fire is detected on a second trip. During this condition, the ECM
monitors the CKP sensor signal every 1,000 engine revolu-
tions.
A misfire malfunction can be detected on any one cylinder or
on multiple cylinders.
Malfunction is detected when multiple cylinders misfire, No. 1 cyl-
inder misfires, No. 2 cylinder misfires, No. 3 cylinder misfires, No.
4 cylinder misfires, No. 5 cylinder misfires and No. 6 cylinder
misfires.
Possible CauseNBEC0490IImproper spark plug
IInsufficient compression
IIncorrect fuel pressure
IThe injector circuit is open or shorted
IInjectors
IIntake air leak
IThe ignition secondary circuit is open or shorted
ILack of fuel
IDrive plate or flywheel
IHeated oxygen sensor 1 (front)
DTC P0300 - P0306 NO.6-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
On Board Diagnosis Logic
EC-320

SEF977Y
Component DescriptionNBEC0191The crankshaft position sensor (POS) is located on the oil pan
facing the gear teeth (cogs) of the signal plate (flywheel). It detects
the crankshaft position signal (1É signal).
The sensor consists of a permanent magnet, core and coil.
When engine is running, the gap between the sensor and the gear
teeth (cogs) will periodically change. Permeability near the sensor
also changes.
Due to the permeability change, the magnetic flux near the core is
changed. Therefore, the voltage signal generated in the coil is
changed.
The ECM receives the voltage signal and detects the crankshaft
position signal (1É signal).
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0492Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
CKPS´RPM (POS)ITachometer: Connect
IRun engine and compare tachometer indication with the CONSULT-II
value.Almost the same speed as the
CONSULT-II value.
DTC P0335 CRANKSHAFT POSITION SENSOR (CKPS) (POS)
Component Description
EC-334

ECM Terminals and Reference Value=NBEC0664Specification 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)
85 YCrankshaft position
sensor (POS)[Engine is running]
IIdle speedApproximately 2.4V
SEF057V
[Engine is running]
IEngine speed is 2,000 rpm.Approximately 2.3V
SEF058V
On Board Diagnosis LogicNBEC0193Malfunction is detected when 1É signal is not entered to ECM for
the first few seconds during engine cranking, or 1É signal is not
entered to ECM during engine running.
Possible CauseNBEC0493IHarness or connectors
(The crankshaft position sensor (POS) circuit is open or
shorted.)
ICrankshaft position sensor (POS)
IStarter motor (Refer to EL section.)
IStarting system circuit (Refer to EL section.)
IDead (Weak) battery
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0335 CRANKSHAFT POSITION SENSOR (CKPS) (POS)
ECM Terminals and Reference Value
EC-335