2001 NISSAN ALMERA diagram

4 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
JEF104Y
3. Disconnect heated oxygen sensor 1 (front) harness connector.
SEF012XA
©GO TO 5.
5 RETIGHTEN HEATED OXYGEN SENSOR 1 (FRONT)
Loosen and retighten corresponding heated oxygen sensor 1 (front).
Tightening torque:
40 - 50 N´m (4.1 - 5.1 kg-m, 30 - 37 ft-lb)
©GO TO 6.
6 CHECK INPUT SIGNAL CIRCUIT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 62 and heated oxygen sensor 1 (front) harness connector terminal 2.
Refer to wiring diagram.
Continuity should exist.
3. Check harness continuity between ECM terminal 62 (or terminal 2) and ground.
Continuity should not exist.
4. Also check harness for 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.
HEATED OXYGEN SENSOR 1 (FRONT)QG
Diagnostic Procedure (Cont'd)
EC-454

Wiring DiagramNJEC1228SEDAN MODELS AND HATCHBACK MODELS WITH
ECM IN ENGINE COMPARTMENT
NJEC1228S03
HEC852
HEATED OXYGEN SENSOR 1 HEATER (FRONT)QG
Wiring Diagram
EC-458

HATCHBACK MODELS WITH ECM IN CABINNJEC1228S04
HEC939
HEATED OXYGEN SENSOR 1 HEATER (FRONT)QG
Wiring Diagram (Cont'd)
EC-459

3 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors F36, E75
+Harness connectors E106, M21 (Sedan), E175, M160 or F113, M169 (Hatchback)
+10A fuse
+Harness for open or short between heated oxygen sensor 1 (front) and 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 1 (front) harness connector terminal 3 and ECM terminal 4.
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 5.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK HEATED OXYGEN SENSOR 1 HEATER (FRONT)
Refer to ªComponent Inspectionº, EC-461.
OK or NG
OK©GO TO 6.
NG©Replace heated oxygen sensor 1 (front).
6 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
SEF935X
Component InspectionNJEC1230HEATED OXYGEN SENSOR 1 HEATER (FRONT)NJEC1230S01Check resistance between terminals 3 and 1.
Resistance: 2.3 - 4.3Wat 25ÉC (77ÉF)
Check continuity between terminals 2 and 1, 3 and 2.
Continuity should not exist.
If NG, replace the heated oxygen sensor 1 (front).
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 1 HEATER (FRONT)QG
Diagnostic Procedure (Cont'd)
EC-461

Wiring DiagramNJEC1237SEDAN MODELS AND HATCHBACK MODELS WITH
ECM IN ENGINE COMPARTMENT
NJEC1237S03
HEC853
HEATED OXYGEN SENSOR 2 (REAR)QG
Wiring Diagram
EC-463

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

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