o2 sensor NISSAN ALMERA 2001 Service Manual

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

Diagnostic ProcedureNJEC1744
1 CHECK OVERALL FUNCTION
1. Start engine and let it idle.
2. Check voltage between ECM terminal 85 and ground.
SEF761Z
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
JEF104Y
©GO TO 3.
CRANKSHAFT POSITION SENSOR (POS)QG
Diagnostic Procedure
EC-487

3 CHECK POWER SUPPLY
1. Disconnect crankshaft position sensor harness connector.
JEF835Z
2. Turn ignition switch ªONº.
3. Check voltage between terminal 3 and ground with CONSULT-II or tester.
SEF113Y
OK or NG
OK©GO TO 5.
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
+Joint connector-4 (If so equipped)
+Joint connector-6 (If so equipped)
+Harness for open or short between joint connector and ECM relay
+Harness for open or short between crankshaft position sensor and joint connector
+Harness for open or short between joint connector and ECM
+ECM relay
©Repair open circuit or short to ground or short to power in harness or connectors.
CRANKSHAFT POSITION SENSOR (POS)QG
Diagnostic Procedure (Cont'd)
EC-488

5 CHECK INPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connectors.
JEF835Z
3. Check continuity between ECM terminal 85 and crankshaft position sensor harness connector terminal 2.
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©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK GROUND CIRCUIT
1. Reconnect ECM harness connector.
2. Check harness continuity between terminal 1 and engine ground.
Refer to wiring diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 8.
NG©GO TO 7.
7 DETECT MALFUNCTIONING PART
Check the following.
+Joint connector-5 (Hatchback models)
+Harness for open between crankshaft position sensor harness connector terminal 1 and engine ground.
©Repair open circuit or short to power in harness or connectors.
8 CHECK CRANKSHAFT POSITION SENSOR
Refer to ªComponent Inspectionº, EC-490.
OK or NG
OK©GO TO 9.
NG©Replace crankshaft position sensor.
9 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
CRANKSHAFT POSITION SENSOR (POS)QG
Diagnostic Procedure (Cont'd)
EC-489

SEF121X
Component InspectionNJEC1745CRANKSHAFT POSITION SENSOR (POS)NJEC1745S011. Disconnect crankshaft position sensor (POS) harness connec-
tor.
2. Loosen the fixing bolt of the sensor.
3. Remove the sensor.
4. Visually check the sensor for chipping.
SEF122X
5. Check resistance as shown in the figure.
Terminal No. (Polarity) ResistanceW[at 25ÉC (77ÉF)]
3 (+) - 1 (±)
Except 0 or¥ 2 (+) - 1 (±)
3 (+) - 2 (±)
If NG, replace crankshaft position sensor.
CRANKSHAFT POSITION SENSOR (POS)QG
Component Inspection
EC-490