EC-304
[QR]
HO2S1
Diagnostic ProcedureBBS005IV
1. CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “HO2S1 MNTR (B1)” in “DATA MONITOR” mode with
CONSULT-II.
3. Keep the engine speed at 2,000 rpm under no load, and make
sure that the monitors fluctuates between LEAN and RICH more
than five times in 10 seconds.
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 Diagnostic test mode - II (Heated oxygen sensor 1 monitor).
Refer to EC-37, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .
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.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to E C - 111 , "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.1 time: RICH → LEAN → RICH
2 times: RICH → LEAN → RICH → LEAN →RICH
SEF820Y
SAT652J
PBIB2160E
HO2S1
EC-305
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3. CHECK HO2S1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect heated oxygen sensor 1 harness connector.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 74 and HO2S1
terminal 4.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
4. CHECK HO2S1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 35 and HO2S1 terminal 1.
Refer to Wiring Diagram.
2. Check harness continuity between ECM terminal 35 or HO2S1 terminal 1 and ground.
Refer to Wiring Diagram.
3. Also check harness for 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
Refer to EC-305, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace heated oxygen sensor 1.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-105, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionBBS005IW
HEATED OXYGEN SENSOR 1
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “MANU TRIG” and adjust “TRIGGER POINT” to 100% in “DATA MONITOR” mode with CONSULT-
II. Continuity should exist.
PBIB2136E
Continuity should exist.
Continuity should not exist.
EC-306
[QR]
HO2S1
3. Select “HO2S1 (B1)” and “HO2S1 MNTR (B1)”.
4. Hold engine speed at 2,000 rpm under no load during the follow-
ing steps.
5. Touch “RECORD” on CONSULT-II screen.
6. Check the following.
“HO2S1 MNTR (B1)” in “DATA MONITOR” mode changes
from “RICH” to “LEAN” to “RICH” more than 5 times in 10 sec-
onds.
5 times (cycles) are counted as shown at right.
“HO2S1 (B1)” voltage goes above 0.6V at least once.
“HO2S1 (B1)” voltage goes below 0.3V at least once.
“HO2S1 (B1)” voltage never exceeds 1.0V.
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 system threads using Oxygen Sensor Thread
Cleaner and approved anti-seize lubricant.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes between ECM terminal 35 (HO2S1 signal) and ground.
3. Check the following with engine speed held at 2,000 rpm con-
stant under no load.
The voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V
more than 5 times within 10 seconds.
The maximum voltage is over 0.6V at least 1 time.
The minimum voltage is below 0.3V at least 1 time.
The voltage never exceeds 1.0V.
1 time: 0 - 0.3V → 0.6 - 1.0V → 0 - 0.3V
2 times: 0 - 0.3V → 0.6 - 1.0V → 0 - 0.3V → 0.6 - 1.0V
→ 0 - 0.3V
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.
SEF646Y
SEF217YA
SEF648Y
MBIB0018E
EC-308
[QR]
HO2S1 HEATER
HO2S1 HEATERPFP:22690
DescriptionBBS005IY
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the heated oxygen sensor 1 heater corresponding to the engine
speed and engine coolant temperature. The duty percent varies with engine coolant temperature when engine
is started.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeBBS005IZ
Specification data are reference values.
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 1
heater controlHeated oxygen sensor 1
heater
Engine coolant temperature sensor Engine coolant temperature
Engine speed rpm Heated oxygen sensor 1 heater
Above 3,600OFF
Below 3,600 after warming up ON
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 HTR (B1)
Engine: After warming up
Engine speed: Below 3,600 rpmON
Engine speed: Above 3,600 rpm OFF
O2SEN HTR DTY
Engine coolant temperature when engine started: More than 80°C
(176°F)
Engine speed: below 3,600 rpmApprox. 50%
EC-310
[QR]
HO2S1 HEATER
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
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.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureBBS005J1
1. CHECK OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Set tester prove between ECM terminal 24 (HO2S1 heater signal) and ground.
5. Start engine and let it idle.
6. Check the voltage under the following conditions.
Verify that the oscilloscope screen shows the signal waves as
shown below.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
24 O/BHeated oxygen sensor 1
heater[Engine is running]
Warm-up condition
Engine speed: Below 3,600 rpmApproximately 7.0V
[Engine is running]
Engine speed: Above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
35 W/B Heated oxygen sensor 1[Engine is running]
Warm-up condition
Engine speed: 2,000 rpm0 - Approximately 1.0V
(Periodically change)
74 BSensor ground
(Heated oxygen sensor)[Engine is running]
Warm-up condition
Idle speedApproximately 0V
PBIB0519E
Conditions Voltage
At idleApproximately 7.0V
Engine speed: Above 3,800 rpm.BATTERY VOLTAGE
(11 - 14V)
MBIB0038EPBIB0519E
HO2S2
EC-315
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Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
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.
Diagnostic ProcedureBBS005J7
1. CHECK OVERALL FUNCTION-I
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 16 (HO2S2 signal) and ground.
6. 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.)
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
2R/LHeated oxygen sensor 2
heater[Engine is running]
Engine speed: Below 3,800 rpm after the
following conditions are met
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for
1 minute under no load0 - 1.0V
[Ignition switch: ON]
Engine stopped
[Engine is running]
Engine speed: Above 3,800 rpmBATTERY VOLTAGE
(11 - 14V)
16 P/B Heated oxygen sensor 2[Engine is running]
Revving engine from idle to 3,000 rpm
quickly after the following conditions are
met
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for
1 minute under no load0 - Approximately 1.0V
74 BSensor ground
(Heated oxygen sensor)[Engine is running]
Warm-up condition
Idle speedApproximately 0V
The voltage does not remain in the range of 0.2 - 0.4V
MBIB0020E
HO2S2
EC-317
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5. CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 16 and HO2S2 terminal 1.
Refer to Wiring Diagram.
2. Check harness continuity between ECM terminal 16 or HO2S2 terminal 1 and ground.
Refer to Wiring Diagram.
3. Also check harness for 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 HEATED OXYGEN SENSOR 2
Refer to EC-317, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace heated oxygen sensor 2.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-105, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionBBS005J8
HEATED OXYGEN SENSOR 2
With CONSULT-II
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select
“HO2S2 (B1)” as the monitor item with CONSULT-II.Continuity should exist.
Continuity should not exist.
SEF662Y
EC-318
[QR]
HO2S2
6. Check “HO2S2 (B1)” at idle speed when adjusting “FUEL INJECTION” to ±25%.
“HO2S2 (B1)” should be above 0.68V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)” should be below 0.50V at least once when the “FUEL INJECTION” is −25%.
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 system threads using Oxygen Sensor Thread
Cleaner and approved anti-seize lubricant.
Without CONSULT-II
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed at between 3,500 and 4,000 rpm for at least 1 minute under no
load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 16 (HO2S2 signal) and ground.
6. 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 during this
procedure.
If the voltage is above 0.68V at step 6, step 7 is not neces-
sary.
7. Keep vehicle idling for 10 minutes, then check voltage. Or check
the voltage when coasting from 80 km/h (50 MPH) in D position
with “OD” OFF.
The voltage should be below 0.50V at least once during this
procedure.
8. If NG, replace heated oxygen sensor 2.
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 system threads using Oxygen Sensor Thread
Cleaner and approved anti-seize lubricant.
Removal and InstallationBBS005J9
HEATED OXYGEN SENSOR 2
Refer to EX-2, "EXHAUST SYSTEM" .
PBIB0551E
MBIB0020E