P1144 HO2S1
EC-239
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
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Do you have CONSULT-III?
YES >> GO TO 2.
NO >> GO TO 3.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and warm it up to normal operating temperature.
2. Stop engine and wait at least 10 seconds.
3. Turn ignition switch ON and select “HO2S1 (B1) P1144” of “HO2S1” in “DTC WORK SUPPORT” mode
with CONSULT-III.
4. Touch “START”.
5. Start engine and let it idle for at least 3 minutes.
NOTE:
Never raise engine speed above 3,600 rpm after this step. If the engine speed limit is exceeded,
return to step 5.
6. When the following conditions are met, “TESTING” will be displayed on the CONSULT-III screen. Maintain
the conditions continuously until “TESTING” changes to “COMPLETED”. (It will take approximately 50
seconds or more.)
CAUTION:
Always drive vehicle at a safe speed.
If “TESTING” is not displayed after 5 minutes, retry from step 2.
7. Touch “SELF-DIAG RESULT”
Which is displayed on CONSULT-III screen?
OK >> INSPECTION END
NG >> Go to EC-239, "
Diagnosis Procedure".
3.PERFORM COMPONENT FUNCTION CHECK
With GST
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes between ECM harness connector terminals as follows under the following condition.
NOTE:
Use component function check to check the overall function of the heated oxygen sensor 1 circuit. During this
check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-239, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001671010
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E15. Refer to Ground Inspection in GI-58, "
Circuit Inspection".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace ground connection.
ENG SPEED 1,375 - 2,600 rpm
VHCL SPEED SE Less than 100 km/h (62 MPH)
B/FUEL SCHDL 3.7 - 10.0 msec
Shift lever Suitable position
(+) (–)
Condition Voltage
Connector Terminal Connector Terminal
F1149
(HO2S1 signal)F11 56Engine speed held at 2,000 rpm
constant under no load The maximum voltage is over 0.8 at
least 1 time.
The minimum voltage is over 0.35 at
least 1 time.
EC-240
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
P1144 HO2S1
2.RETIGHTEN HEATED OXYGEN SENSOR 1
Loosen and retighten heated oxygen sensor 1. Refer to EM-159, "
Removal and Installation".
>> GO TO 3.
3.CLEAR THE SELF-LEARNING DATA
1. Clear the mixture ratio self-learning value, refer to EC-29, "
MIXTURE RATIO SELF-LEARNING VALUE
CLEAR : Special Repair Requirement".
2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 detected or difficult to start engine?
Yes >> Perform trouble diagnosis for DTC P0172. Refer to EC-179, "DTC Logic".
No >> GO TO 4
4.CHECK HO2S1 CONNECTOR FOR WATER
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 1 harness connector.
3. Check connectors for water.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace harness or connectors.
5.CHECK HEATED OXYGEN SENSOR 1 HEATER
Refer to EC-164, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace heated oxygen sensor 1.
6.CHECK HEATED OXYGEN SENSOR 1
Refer to EC-150, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace heated oxygen sensor 1.
7.CHECK INTERMITTENT INCIDENT
Refer to GI-55, "
Intermittent Incident".
>>INSPECTION END
Component InspectionINFOID:0000000001671011
1.INSPECTION START
Do you have CONSULT-III?
Do you have CONSULT-III?
YES >> GO TO 2.
NO >> GO TO 3.
2.CHECK HEATED OXYGEN SENSOR 1
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Set “POST TRIGGER” to 100% in “DATA MONITOR” mode with CONSULT-III.
3. Select “HO2S1 (B1)” and “HO2S1 MNTR (B1)”.
4. Hold engine speed at 2,000 rpm under no load during the following steps.
5. Touch “RECORD” on CONSULT-III screen.Water should not exist.
P1144 HO2S1
EC-241
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
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6. Check the following.
- “HO2S1 MNTR (B1)” in “DATA MONITOR” mode changes from
“RICH” to “LEAN” to “RICH” more than 5 times in 10 seconds.
5 times (cycles) are counted as shown in the figure.
- “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 tool and approved anti-seize lubricant.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 4.
3.CHECK HEATED OXYGEN SENSOR 1
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Check the voltage between ECM harness connector terminals as follows under the following condition.
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 tool and approved anti-seize lubricant.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 4.
4.REPLACE HEATED OXYGEN SENSOR 1
Replace heated oxygen sensor 1.
CAUTION:
SEF217YA
JMBIA0352ZZ
(+) (–)
Condition Voltage
Connector Terminal Connector Terminal
F1149
(HO2S1 signal)F11 56Engine speed
held at 2,000 rpm
constant 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
EC-242
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
P1144 HO2S1
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 tool and approved anti-seize lubricant.
>> INSPECTION END
P1146 HO2S2
EC-243
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
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P1146 HO2S2
DescriptionINFOID:0000000001671012
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the heated oxygen sensor 1 are
shifted, the air-fuel ratio is controlled to stoichiometric, by the signal
from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
DTC LogicINFOID:0000000001671013
DTC DETECTION LOGIC
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the heated oxygen sensor 1. The oxygen
storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the minimum voltage of the sensor
is sufficiently low during the various driving condition such as fuel-
cut.
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
Do you have CONSULT-III?
Do you have CONSULT-III?
YES >> GO TO 2.
NO >> GO TO 11.
2.PRECONDITIONING
“COMPLETED” will appear on CONSULT-III screen when all tests “COND1”, “COND2” and “COND3” are
completed.
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
For the best results, perform ″DTC WORK SUPPORT″ at a temperature of 0 to 30°C (32 to 86°F).
Never stop engine during this procedure. If the engine is stopped, retry this procedure from step 2 in
Procedure for COND1.
CAUTION:
Always drive at safe speed.
SEF327R
PBIB0554E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1146Heated oxygen sensor 2
minimum voltage moni-
toringThe minimum voltage from the sensor is not
reached to the specified voltage. Harness or connectors
(The sensor circuit is open or shorted)
Heated oxygen sensor 2
Fuel pressure
Fuel injector
Intake air leaks
P1146 HO2S2
EC-245
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
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CAN NOT BE DIAGNOSED>>GO TO 10.
10.PERFORM PROCEDURE FOR COND3-II
1. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
2. Turn ignition switch ON and select “COOLAN TEMP/S” in “DATA MONITOR” mode with CONSULT-III.
3. Start engine and warm it up while monitoring “COOLAN TEMP/S” indication on CONSULT-III.
4. When “COOLAN TEMP/S” indication reaches to 70°C (158°F).
>> GO TO 5.
11 .PREFORM COMPONENT FUNCTION CHECK
Perform component function check. Refer to EC-245, "
Component Function Check".
NOTE:
Use component function check the overall function of the heated oxygen sensor 2 circuit. During this check, a
1st trip DTC might not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-246, "
Diagnosis Procedure".
Component Function CheckINFOID:0000000001671014
1.PERFORM COMPONENT FUNCTION CHECK-I
With GST
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. Check the voltage between ECM harness connector terminals as follows under the following condition.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.PERFORM COMPONENT FUNCTION CHECK-II
Check the voltage between ECM harness connector terminals as follows under the following condition.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 3.
3.PERFORM COMPONENT FUNCTION CHECK-III
Check the voltage between ECM harness connector terminals as follows under the following condition.
(+) (–)
Condition Voltage
Connector Terminal Connector Terminal
F1150
(HO2S2 signal)F11 59Revving up to 4,000 rpm un-
der no load at least 10 timesThe voltage should be above 0.68V at least
once during this procedure.
(+) (–)
Condition Voltage
Connector Terminal Connector Terminal
F1150
(HO2S2 signal)F11 59Keeping engine speed at idle
for 10 minutesThe voltage should be above 0.68V at least
once during this procedure.
EC-246
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
P1146 HO2S2
Always drive vehicle at a safe speed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-246, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001671015
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E15. Refer to Ground Inspection in GI-58, "
Circuit Inspection".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace ground connection.
2.CLEAR THE SELF-LEARNING DATA
1. Clear mixture ratio self-learning value, refer to EC-29, "
MIXTURE RATIO SELF-LEARNING VALUE
CLEAR : Special Repair Requirement".
2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 detected? Is it difficult to start engine?
YES >> Perform trouble diagnosis for DTC P0172. Refer to EC-183, "DTC Logic".
NO >> GO TO 3.
3.CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between HO2S2 harness connector and ECM harness connector.
5. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between HO2S2 harness connector and ECM harness connector.
2. Check the continuity between HO2S2 harness connector or ECM harness connector and ground.
(+) (–)
Condition Voltage
Connector Terminal Connector Terminal
F1150
(HO2S2 signal)F11 59Coasting from 80 km/h (50 MPH)
in D position (A/T), 4th gear posi-
tion (M/T)The voltage should be above 0.68V at
least once during this procedure.
HO2S2 ECM
Continuity
Connector Terminal Connector Terminal
F13 1 F11 59 Existed
HO2S2 ECM
Continuity
Connector Terminal Connector Terminal
F13 4 F11 50 Existed
HO2S2 ECM
Ground Continuity
Connector Terminal Connector Terminal
F13 4 F11 50 Ground Not existed
P1146 HO2S2
EC-247
< COMPONENT DIAGNOSIS >[HR16DE (WITH EURO-OBD)]
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3. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK HEATED OXYGEN SENSOR 2
Refer to EC-247, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 6.
6.REPLACE HEATED OXYGEN SENSOR 2
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 tool and approved anti-seize lubricant.
>> INSPECTION END
7.CHECK INTERMITTENT INCIDENT
Refer to GI-55, "
Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001671016
1.INSPECTION START
Do you have CONSULT-III?
Do you have CONSULT-III?
YES >> GO TO 2.
NO >> GO TO 3.
2.CHECK HEATED OXYGEN SENSOR 2
With CONSULT-III
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select “HO2S2 (B1)” as the monitor item with
CONSULT-III.
7. 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%.
Is the inspection result normal?
PBIB0551E