Page 842 of 3051

Diagnostic ProcedureNLEC1221
1 INSPECTION START
Do you have CONSULT-II?
YesorNo
Ye s©GO TO 2.
No©GO TO 3.
2 CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªHO2S1 MNTR (B1)º in ªDATA MONITORº mode with CONSULT-II.
3. Keep the engine speed at 2,000 rpm under no load, and make sure that the monitors fluctuate between LEAN and
RICH more than five times in 10 seconds.
SEF218Z
OK or NG
OK©INSPECTION END
NG©GO TO 4.
3 CHECK OVERALL FUNCTION
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine and wait at least 10 seconds.
3. Set ECM in ªDiagnostic test mode - II [Heated oxygen sensor 1 monitor (front)]º. Refer to ªHow to Switch Diagnostic
Test Modesº, EC-73.
4. Keep the engine speed at 2,000 rpm under no load, and make sure that the MI comes ON more than five times in 10
seconds.
SAT652J
OK or NG
OK©INSPECTION END
NG©GO TO 4.
HEATED OXYGEN SENSOR 1 (FRONT)QG18DE
Diagnostic Procedure
EC-417
Page 854 of 3051
Diagnostic ProcedureNLEC1238
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.
SEF240Z
OK or NG
OK©INSPECTION END
NG©GO TO 3.
HEATED OXYGEN SENSOR 2 (REAR)QG18DE
Diagnostic Procedure
EC-429
Page 856 of 3051

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 power.
OK or NG
OK©GO TO 7.
NG©Repair open circuit or short to power in harness or connectors.
7 CHECK HEATED OXYGEN SENSOR 2 (REAR)
Refer to ªComponent Inspectionº, EC-431.
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-145.
©INSPECTION END
SEF662Y
Component InspectionNLEC1239HEATED OXYGEN SENSOR 2 (REAR)NLEC1239S01With 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)QG18DE
Diagnostic Procedure (Cont'd)
EC-431
Page 857 of 3051

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.
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)QG18DE
Component Inspection (Cont'd)
EC-432
Page 861 of 3051
Diagnostic ProcedureNLEC1246
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.
SEF639Z
3. Turn ignition switch ªONº.
4. Check voltage between terminal 2 and ground.
SEF218W
Voltage: Battery voltage
OK or NG
OK©GO TO 4.
NG©GO TO 3.
HEATED OXYGEN SENSOR 2 HEATER (REAR)QG18DE
Diagnostic Procedure
EC-436
Page 898 of 3051

8 CHECK VACUUM HOSES AND TUBES
1. Disconnect vacuum hoses between the air control valve (Power steering) and vacuum port, air control valve (Power
steering) and air duct.
2. Check hoses and tubes for cracks, clogging, improper connection or disconnection.
SEF109L
OK or NG
OK©GO TO 9.
NG©Repair hoses or tubes.
9 CHECK IACV-AAC VALVE
Refer to ªComponent Inspectionº, EC-474.
OK or NG
OK©GO TO 11.
NG©GO TO 10.
10 REPLACE IACV-AAC VALVE
1. Replace IACV-AAC valve assembly.
2. Perform ªIdle Air Volume Learningº, EC-57.
Is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©INSPECTION END
INCMP©Follow the construction of ªIdle Air Volume Learningº.
11 CHECK TARGET IDLE SPEED
1. Turn ignition switch ªOFFº.
2. Reconnect all harness connectors and vacuum hoses.
3. Start engine and warm it up to normal operating temperature.
4. Also warm up transmission to normal operating temperature.
+For M/T models, drive vehicle for 10 minutes.
5. Stop vehicle with engine running.
6. Check target idle speed.
700±50 rpm
OK or NG
OK©GO TO 12.
NG©Perform ªIdle Air Volume Learningº, EC-57.
12 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-145.
©INSPECTION END
IDLE AIR CONTROL VALVE (IACV) Ð
AUXILIARY AIR CONTROL (AAC) VALVE
QG18DE
Diagnostic Procedure (Cont'd)
EC-473
Page 941 of 3051

System DescriptionNLEC0444
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed
Fuel pump
controlFuel pump relay Camshaft position sensor (PHASE) Engine speed and cylinder number
Ignition switch Ignition signal and start signal
The ECM activates the fuel pump for several seconds after the ignition switch is turned on to improve engine
startability. If the ECM receives a 180É signal from the camshaft position sensor, it knows that the engine is
rotating, and causes the pump to perform. If the 180É signal is not received when the ignition switch is on, the
engine stalls. The ECM stops pump operation and prevents battery discharging, thereby improving safety. The
ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn controls the
fuel pump.
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second
Engine running and cranking Operates
When engine is stopped (Signal is not sent from crankshaft position sensor
and camshaft position sensor.)Stops in 1.5 seconds
Except as shown aboveStops
SEF605X
Component DescriptionNLEC0501A turbine type design fuel pump is used in the fuel tank.
CONSULT-II Reference Value in Data Monitor
Mode
NLEC0445
MONITOR ITEM CONDITION SPECIFICATION
FUEL PUMP RLY+Ignition switch is turned to ON (Operates for 1 second)
+Engine running and cranking
+When engine is stopped (stops in 1.5 seconds)ON
+Except as shown above OFF
FUEL PUMPQG18DE
System Description
EC-516
Page 957 of 3051
Diagnostic ProcedureNLEC0590
1 CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower switch ªONº.
3. Check voltage between ECM terminal 74 and ground with CONSULT-II or tester.
SEF952XA
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Turn A/C switch and blower switch ªOFFº.
2. Stop engine.
3. Disconnect refrigerant pressure sensor harness connector.
JEF147Y
4. Turn ignition switch ªONº.
5. Check voltage between refrigerant pressure sensor terminal 3 and ground with CONSULT-II or tester.
SEF953X
OK or NG
OK©GO TO 4.
NG©GO TO 3.
REFRIGERANT PRESSURE SENSORQG18DE
Diagnostic Procedure
EC-532