2001 NISSAN ALMERA o2 sensor

Diagnostic ProcedureNJEC1246
1 CHECK OVERALL FUNCTION
Without CONSULT-II
1. Start engine and drive the vehicle at over 70 km/h (43 MPH) for 2 consecutive minutes.
2. Stop vehicle and keep the engine running.
3. Set the voltmeter probe between ECM terminals 3 [HO2S2 HTR (B1) signal] and ground.
4. Check the voltage under the following conditions.
SEF241Z
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect heated oxygen sensor 2 (rear) harness connector.
SEF160Z
3. Turn ignition switch ªONº.
4. Check voltage between terminal 2 and ground.
SEF218W
OK or NG
OK©GO TO 4.
NG©GO TO 3.
HEATED OXYGEN SENSOR 2 HEATER (REAR)QG
Diagnostic Procedure
EC-472

3 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E75, F36
+Harness connectors M21, E106 (Sedan), M160, E175 (Hatchback)
+Harness for open or short between heated oxygen sensor 2 (rear) and fuse
+10A fuse
©Repair harness or connectors.
4 CHECK GROUND CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between heated oxygen sensor 2 (rear) harness connector terminal 3 and ECM terminal 3.
Refer to wiring diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 6.
NG©GO TO 5.
5 DETECT MALFUNCTIONING PART
Check the harness for open or short between heated oxygen sensor 2 heater (rear) and ECM.
©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK HEATED OXYGEN SENSOR 2 HEATER (REAR)
Refer to ªComponent Inspectionº, EC-474.
OK or NG
OK©GO TO 7.
NG©Replace heated oxygen sensor 2 (rear).
7 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
HEATED OXYGEN SENSOR 2 HEATER (REAR)QG
Diagnostic Procedure (Cont'd)
EC-473

SEF221W
Component InspectionNJEC1247HEATED OXYGEN SENSOR 2 HEATER (REAR)NJEC1247S01Check the following.
1. Check resistance between terminals 1 and 4.
Resistance: 2.3 - 4.3Wat 25ÉC (77ÉF)
2. Check continuity.
Terminal No. Continuity
1 and 2, 3, 4
No
4 and 1, 2, 3
If NG, replace the heated oxygen sensor 2 (rear).
CAUTION:
+Discard any heated oxygen sensor which has been
dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
+Before installing new oxygen sensor, clean exhaust sys-
tem threads using Oxygen Sensor Thread Cleaner tool
and approved anti-seize lubricant.
HEATED OXYGEN SENSOR 2 HEATER (REAR)QG
Component Inspection
EC-474

DescriptionNJEC1248SYSTEM DESCRIPTIONNJEC1248S01
Sensor Input Signal to ECMECM func-
tionActuator
Throttle position sensor Throttle position
Swirl con-
trol valve
system
controlSwirl control valve control sole-
noid valve via swirl control
valve Ignition switch Start signal
Crankshaft position sensor (POS) Engine speed
Camshaft position sensor (PHASE) Engine speed and cylinder number
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 control 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 combus-
tion chamber.
Because of this operation, this system tends to increase the burning 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.
The solenoid valve controls swirl control valve's shut/open condition. This solenoid valve is operated by the
ECM.
OPERATIONNJEC1248S02
Engine coolant tempera-
tureThrottle position sensor
(Idle position)Engine speedSwirl control valve con-
trol solenoid valveSwirl control valve
15 - 40ÉC
(59 - 104ÉF)ON Ð
ON Closed
OFF Below 2,400 rpm*
Except above OFF Open
*: The value may vary according to accelerator pedal operation.
SEF081X
CONSULT-II Reference Value in Data Monitor
Mode
NJEC1249Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
SWRL CONT S/V+Engine speed: IdleEngine coolant temperature is
between 15ÉC (59ÉF) to 40ÉC
(104ÉF).ON
Engine coolant temperature is
above 40ÉC (104ÉF).OFF
SWIRL CONTROL VALVE CONTROL SYSTEM (WHERE FITTED)QG
Description
EC-475

3 CHECK OVERALL FUNCTION
Without CONSULT-II
1. Disconnect engine coolant temperature sensor harness connector.
2. Connect a resistor (1.5 - 2.0 kW) between terminals of engine coolant temperature sensor harness connector.
SEF982UB
3. Start engine and let it idle.
4. In idle with the swirl control valve set to CLOSE, verify by observing the lever movement that the valve changes to
OPEN when the engine rpm exceeds 2,400 rpm.
SEF242Z
OK or NG
OK©INSPECTION END
NG©Remove resistor. GO TO 4.
SWIRL CONTROL VALVE CONTROL SYSTEM (WHERE FITTED)QG
Diagnostic Procedure (Cont'd)
EC-479

SEF058X
JEF835Z
Component DescriptionNJEC1741The crankshaft position sensor (POS) is located on the right-rear
wall of the cylinder block in relation to the signal plate at the rear
end of the crankshaft.
The sensor consists of a permanent magnet, and hall IC.
When the engine is running, the high and low parts of the teeth
cause the gap with the sensor to change.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor
changes.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
ECM Terminals and Reference ValueNJEC1742Specification 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 (AC Voltage)
85 RCrankshaft position
sensor (POS)[Engine is running]
+Warm-up condition
+Idle speed3-4V
SEF979W
[Engine is running]
+Engine speed is 2,000 rpm3-4V
SEF980W
CRANKSHAFT POSITION SENSOR (POS)QG
Component Description
EC-484

Wiring DiagramNJEC1743SEDAN MODELS AND HATCHBACK MODELS WITH ECM IN ENGINE COMPARTMENTNJEC1743S01
NEF331A
CRANKSHAFT POSITION SENSOR (POS)QG
Wiring Diagram
EC-485

HATCHBACK MODELS WITH ECM IN CABINNJEC1743S02
HEC981
CRANKSHAFT POSITION SENSOR (POS)QG
Wiring Diagram (Cont'd)
EC-486