Page 1195 of 2898
HATCHBACK MODELS WITH ECM IN CABINNJEC1245S04
HEC943
HEATED OXYGEN SENSOR 2 HEATER (REAR)QG
Wiring Diagram (Cont'd)
EC-471
Page 1196 of 2898
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
Page 1197 of 2898

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
Page 1198 of 2898
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
Page 1302 of 2898

CONSULT-II Reference Value in Data Monitor
Mode
NJEC0548Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
LOAD SIGNAL+Ignition switch: ONRear window defogger is operating
and/or lighting switch is on.ON
Rear window defogger is not oper-
ating and lighting switch is not on.OFF
HEATER FAN SW+Ignition switch: ONHeater fan motor is operating. ON
Heater fan motor is not operating. OFF
ECM Terminals and Reference ValueNJEC0549Specification 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.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
50 L/BElectric load signal
(Load switch)[Engine is running]
+Rear window defogger is operating and/or lighting
switch is onBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Rear window defogger is not operating and lighting
switch is not onApproximately 0V
51 LG/B Heater fan motor switch[Engine is running]
+Heater fan motor is operatingApproximately 0V
[Engine is running]
+Heater fan motor is not operatingApproximately 5V
ELECTRICAL LOAD SIGNALQG
CONSULT-II Reference Value in Data Monitor Mode
EC-578
Page 1313 of 2898
21 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M63, F102
+Harness connectors M159, F174
+Diode E177
+Harness for open and short between ECM and lighting switch connector
©Repair open circuit or short to ground or short to power in harness or connectors.
22 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
Diagnostic Procedure Ð Heater Control Panel
(Fan Switch) Ð
NJEC0585
1 CHECK CIRCUIT OVERALL FUNCTION
1. Start engine.
2. Heater fan motor switch ªONº.
3. Check voltage between ECM terminal 51 and ground under the following conditions.
SEF620Y
OK or NG
OK©INSPECTION END
NG©GO TO 2.
ELECTRICAL LOAD SIGNALQG
Diagnostic Procedure Ð Load Signal Ð (Cont'd)
EC-589
Page 1314 of 2898

2 CHECK INPUT SIGNAL CIRCUIT
1. Stop engine.
2. Disconnect ECM harness connector.
3. Disconnect heater control panel fan switch harness connector.
4. Check harness continuity between ECM terminal 51 and heater fan switch harness connector terminal 18.
Refer to wiring diagram.
Continuity should exist.
5. Also check harness for short to ground and short to power.
OK or NG
OK©Refer to HA-48, ªBLOWER MOTORº.
NG©GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M94, F106 (Sedan)
+Harness connectors M73, F111 or M169, F113 (Hatchback)
+Harness for open and short between ECM and heater fan motor switch
©Repair open circuit or short to ground or short to power in harness or connectors.
SEF145XC
Component InspectionNJEC0586REAR WINDOW DEFOGGER RELAYNJEC0586S01Check continuity between terminals 3 and 5.
Conditions Continuity
12V direct current supply between terminals 1 and 2 Yes
No current supply No
If NG, replace relay.
ELECTRICAL LOAD SIGNALQG
Diagnostic Procedure Ð Heater Control Panel (Fan Switch) Ð (Cont'd)
EC-590
Page 1317 of 2898

Fuel Pressure RegulatorNJEC0467
Fuel pressure at idling
kPa (bar, kg/cm2, psi)Vacuum hose is connected Approximately 235 (2.35, 2.4, 34)
Vacuum hose is disconnected Approximately 294 (2.94, 3.0, 43)
Idle Speed and Ignition TimingNJEC0468
Target idle speed* rpmM/T: 700±50
A/T: 800±50
Air conditioner: ON rpm825 or more
Ignition timingM/T: 8±5É BTDC
A/T: 10±5É BTDC
Throttle position sensor idle position V 0.15 - 0.85
*: Under the following conditions:
+Air conditioner switch: OFF
+Electrical load: OFF (Lights, heater fan & rear window defogger)
+Steering wheel: Kept in straight-ahead position
Mass Air Flow SensorNJEC0470
Supply voltage (Heater) VBattery voltage (11 - 14)
Supply voltage (Sensor) VApproximately 5
Output voltage V1.0 - 1.7*
Mass air flow
(Using CONSULT-II or GST) g´m/sec1.0 - 4.0 at idle*
5.0 - 10.0 at 2,500 rpm*
*: Engine is warmed up to normal operating temperature and idling under no-load.
Intake Air Temperature SensorNJEC0480
Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
80 (176) 0.27 - 0.38
Engine Coolant Temperature SensorNJEC0471
Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
Throttle Position SensorNJEC0477
Throttle valve conditions Voltage (V)
Completely closed0.15 - 0.85
Completely open3.5 - 4.7
Heated Oxygen Sensor 1 Heater (Front)NJEC0478
Resistance [at 25ÉC (77ÉF)]W2.3 - 4.3
Heated Oxygen Sensor 2 Heater (Rear)NJEC0483
Resistance [at 25ÉC (77ÉF)]W2.3 - 4.3
SERVICE DATA AND SPECIFICATIONS (SDS)QG
Fuel Pressure Regulator
EC-593