2001 NISSAN ALMERA o2 sensor

HATCHBACK MODELS WITH ECM IN CABINNJEC1237S04
HEC941
HEATED OXYGEN SENSOR 2 (REAR)QG
Wiring Diagram (Cont'd)
EC-464

Diagnostic ProcedureNJEC1238
1 CHECK OVERALL FUNCTION-I
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 voltmeter probes between ECM terminals 63 [HO2S2 (B1) signal] and ground.
4. Check the voltage while revving up to 4,000 rpm under no load at least 10 times.
(Depress and release the accelerator pedal as quickly as possible.)
SEF240Z
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 CHECK OVERALL FUNCTION-II
Keep engine at idle for 10 minutes, then check the voltage between ECM terminal 63 and ground, or check the voltage
when coasting at 80 km/h (50 MPH) in 3rd gear (M/T), ªDº position with ªODº OFF (A/T).
SEF240Z
OK or NG
OK©INSPECTION END
NG©GO TO 3.
HEATED OXYGEN SENSOR 2 (REAR)QG
Diagnostic Procedure
EC-465

3 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
JEF104Y
©GO TO 4.
4 CHECK INPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect heated oxygen sensor 2 (rear) harness connector and ECM harness connector.
SEF160Z
3. Check harness continuity between ECM terminal 63 and heated oxygen sensor 2 (rear) harness connector terminal 1.
Refer to wiring diagram.
Continuity should exist.
4. Check harness continuity between ECM terminal 63 [or heated oxygen sensor 2 (rear) harness connector terminal 1]
and ground.
Continuity should not exist.
5. 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 (rear) and ECM.
©Repair open circuit or short to ground or short to power in harness or connectors.
HEATED OXYGEN SENSOR 2 (REAR)QG
Diagnostic Procedure (Cont'd)
EC-466

6 CHECK GROUND CIRCUIT
1. Check harness continuity between heated oxygen sensor 2 (rear) harness connector terminal 4 and body ground.
Refer to wiring diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 7.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
7 CHECK HEATED OXYGEN SENSOR 2 (REAR)
Refer to ªComponent Inspectionº, EC-467.
OK or NG
OK©GO TO 8.
NG©Replace heated oxygen sensor 2 (rear).
8 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
SEF662Y
Component InspectionNJEC1239HEATED OXYGEN SENSOR 2 (REAR)NJEC1239S01With CONSULT-II
1) Start engine and drive vehicle at a speed of more than 70 km/h
(43 MPH) for 2 consecutive minutes.
2) Stop vehicle with engine running.
3) Select ªFUEL INJECTIONº in ªACTIVE TESTº mode, and
select ªHO2S2 (B1)º as the monitor item with CONSULT-II.
4) Check ªHO2S2 (B1)º at idle speed when adjusting ªFUEL
INJECTIONº to±25%.
ªHO2S2 (B1)º should be above 0.68V at least once when
the ªFUEL INJECTIONº is +25%. ªHO2S2 (B1)º should be
below 0.56V at least once when the ªFUEL INJECTIONº is
þ25%.
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.
SEF244YA
HEATED OXYGEN SENSOR 2 (REAR)QG
Diagnostic Procedure (Cont'd)
EC-467

SEF032X
Without CONSULT-II
1) Start engine and drive vehicle at a speed of more than 70 km/h
(43 MPH) for 2 consecutive minutes.
2) Stop vehicle with engine running.
3) Set voltmeter probes between ECM terminals 63 (HO2S2 sig-
nal) and engine ground.
4) Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.68V at least once.
If the voltage is above 0.68V at step 4, step 5 is not nec-
essary.
5) Check the voltage when revving up to 6,000 rpm under no
load. Or keep vehicle at idling for 10 minutes, then check the
voltage. Or check the voltage when coasting from 80 km/h (50
MPH) in 3rd gear position (M/T), D position with ªODº OFF
(A/T).
The voltage should be below 0.56V at least once.
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 (REAR)QG
Component Inspection (Cont'd)
EC-468

DescriptionNJEC1240SYSTEM DESCRIPTIONNJEC1240S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speedHeated
oxygen
sensor 2
heater
(rear) con-
trolHeated oxygen sensor 2 heater
(rear)
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater (rear) corresponding to the engine
speed.
OPERATIONNJEC1240S02
Engine condition Heated oxygen sensor 2 heater (rear)
Engine stopped OFF
Engine is running. After driving for 2 minutes at a speed
of 70 km/h (43 MPH) or moreON
Engine speed above 3,600 rpm OFF
CONSULT-II Reference Value in Data Monitor
Mode
NJEC1241Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)+Engine speedBelow 3,600 rpm [After driving for 2 minutes at a
speed of 70 km/h (43 MPH) or more]ON
Above 3,600 rpm OFF
+Ignition switch ON (Engine stopped) OFF
ECM Terminals and Reference ValueNJEC1242Specification 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 W/RHeated oxygen sensor 2
heater (rear)[Engine is running]
+Engine speed is below 3,600 rpm [After driving
for 2 minutes at a speed of 70 km/h (43 MPH) or
more]0-1V
[Engine is running]
+Engine speed is above 3,600 rpm
BATTERY VOLTAGE
(11 - 14V)
[Ignition switch ªONº]
+Engine stopped
HEATED OXYGEN SENSOR 2 HEATER (REAR)QG
Description
EC-469

Wiring DiagramNJEC1245SEDAN MODELS AND HATCHBACK MODELS WITH
ECM IN ENGINE COMPARTMENT
NJEC1245S03
HEC854
HEATED OXYGEN SENSOR 2 HEATER (REAR)QG
Wiring Diagram
EC-470

HATCHBACK MODELS WITH ECM IN CABINNJEC1245S04
HEC943
HEATED OXYGEN SENSOR 2 HEATER (REAR)QG
Wiring Diagram (Cont'd)
EC-471