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 air fuel ratio (A/F) 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 voltage from approximately 1 V in richer conditions to 0 V in leaner conditions.
Under normal conditions the heated oxygen sensor 2 is not used for engine control operation.
DTC Logic
DTC DETECTION LOGIC
The heated oxygen sensor 2 has a much longer switching time between rich and lean than the air fuel ratio (A/F) 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 maximum voltage of the sensor is sufficiently high during various driving conditions such as fuel cut.
DTC CONFIRMATION PROCEDURE 1.Inspection START
Will CONSULT-III be used?
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 5. 2.PRECONDITIONING
If DTC confirmation Procedure has been previously conducted, always perform the following before conducting the next test.
Turn ignition switch OFF and wait at least 10 seconds.
Turn ignition switch ON.
Turn ignition switch OFF and wait at least 10 seconds. TESTING CONDITION:
For better results, perform "DTC WORK SUPPORT" at a temperature of 0 to 30°C (32 to 86°F) .
>> GO TO 3. 3.PERFORM DTC CONFIRMATION PROCEDURE With CONSULT-III
Turn ignition switch ON and select "DATA MONITOR" mode with CONSULT-III.
Start engine and warm it up to the normal operating temperature.
Turn ignition switch OFF and wait at least 10 seconds.
Turn ignition switch ON.
Turn ignition switch OFF and wait at least 10 seconds.
Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
Let engine idle for 1 minute.
Check that "COOLAN TEMP/S" indicates more than 70°C (158°F) . If not, warm up engine and go to next step when "COOLAN TEMP/S" indication reaches 70°C (158°F) .
Open engine hood.
Select "HO2S2 (B1) P1147" (for DTC P0137) or "HO2S2 (B2) P1167" (for DTC P0157) of "HO2S2" in "DTC WORK SUPPORT" mode with CONSULT-III display.
Follow the instruction of CONSULT-III.
NOTE:
It will take at most 10 minutes until "COMPLETED" is displayed.
Touch "SELF-DIAG RESULTS". Which is displayed on CONSULT-III screen?
OK >> Inspection END
NG >> Go to Diagnosis Procedure.
CANNOT BE DIAGNOSED>>GO TO 4. 4.PERFORM DTC CONFIRMATION PROCEDURE AGAIN
Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
Perform DTC confirmation procedure again. >> GO TO 3.
5.PERFORM COMPONENT FUNCTION CHECK
Perform component function check. Refer to Component Function Check.
NOTE:
Use component function check to 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 Diagnosis Procedure.
Component Function Check 1.PERFORM COMPONENT FUNCTION CHECK-I Without CONSULT-III
Start engine and warm it up to the normal operating temperature.
Turn ignition switch OFF and wait at least 10 seconds.
Turn ignition switch ON.
Turn ignition switch OFF and wait at least 10 seconds.
Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
Let engine idle for 1 minute.
Check the voltage between ECM harness connector terminals under the following conditions.
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 under the following conditions.
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 under the following conditions.
Is the Inspection result normal?
YES >> Inspection END
NO >> Go to Diagnosis Procedure.
Check the continuity between heated oxygen sensor 2 (HO2S2) harness connector and ECM harness connector.
Also check harness for short to ground and short to power. Is the Inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit, short to ground or short to power in harness or connectors. 4.CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
Check the continuity between HO2S2 harness connector and ECM harness connector.
Check the continuity between HO2S2 harness connector and ground, or ECM harness connector and ground.
Also check harness for short to power. Is the Inspection result normal?
YES >> GO TO 5.
NO >> Repair open circuit, short to ground or short to power in harness or connectors. 5.CHECK HEATED OXYGEN SENSOR 2
Refer to Component Inspection.
Is the Inspection result normal?
YES >> GO TO 7.
NO >> GO TO 6. 6.REPLACE HEATED OXYGEN SENSOR 2
Replace malfunctioning 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 ThreadCleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant (commercial service tool).
Component Inspection 1.Inspection START
Will CONSULT-III be used?
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 3. 2.CHECK HEATED OXYGEN SENSOR 2 With CONSULT-III
Turn ignition switch ON and select "DATA MONITOR" mode with CONSULT-III.
Start engine and warm it up to the normal operating temperature.
Turn ignition switch OFF and wait at least 10 seconds.
Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
Let engine idle for 1 minute.
Select "FUEL INJECTION" in "ACTIVE TEST" mode, and select "HO2S2 (B1)/(B2)" as the monitor item with CONSULT-III.
Check "HO2S2 (B1)/(B2)" at idle speed when adjusting "FUEL INJECTION" to ±25%.
"HO2S2 (B1)/(B2)" should be above 0.68 V at least once when the "FUEL INJECTION" is + 25%. "HO2S2 (B1)/(B2)" should be below 0.18 V at least once when the "FUEL INJECTION" is - 25%.
Is the Inspection result normal?
YES >> Inspection END
NO >> GO TO 6. 3.CHECK HEATED OXYGEN SENSOR 2-I Without CONSULT-III
Start engine and warm it up to the normal operating temperature.
Turn ignition switch OFF and wait at least 10 seconds.
Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
Let engine idle for 1 minute.
Check the voltage between ECM harness connector terminals under the following conditions.
Is the Inspection result normal?
YES >> Inspection END
NO >> GO TO 4. 4.CHECK HEATED OXYGEN SENSOR 2-II
Check the voltage between ECM harness connector terminals under the following conditions.
Is the Inspection result normal?
YES >> Inspection END
NO >> GO TO 5. 5.CHECK HEATED OXYGEN SENSOR 2-III
Check the voltage between ECM harness connector terminals under the following conditions.
Is the Inspection result normal?
YES >> Inspection END
NO >> GO TO 6. 6.REPLACE HEATED OXYGEN SENSOR 2
Replace malfunctioning 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 [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant (commercial service tool). >> Inspection END