P0144
DTC P0144 HO2S3
Component Description
The heated oxygen sensor 3, after ADS-TWC (Adsorber pre-catalyst), monitors the oxygen level in the exhaust gas.
This sensor is used for recovery control of air fuel ratio after the fuel cut operation.
This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions.
Consult-II Reference Value In Data Monitor Mode:
On Board Diagnosis Logic
The heated oxygen sensor 3 has a much longer switching time between rich and lean than air fuel ratio (A/F) sensor 1. The oxygen storage capacity before the TWC (Manifold three way catalyst) causes the longer switching time. To judge the malfunctions of heated oxygen sensor 3, ECM monitors whether or not the voltage is too high during various driving conditions such as fuel-cut.
DTC Confirmation Procedure
CAUTION: Always drive vehicle at a safe speed.
NOTE: If "DTC Confirmation Procedure" has been previously conducted, always turn ignition switch "OFF" and wait at least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT-II.
2. Start engine and drive vehicle at a speed of more than 70 km/h (43 MPH) for 2 consecutive minutes.
3. Stop vehicle with engine running.
4. Let engine idle for 1 minute.
5. Maintain the given conditions for at least 5 consecutive seconds.
6. If 1st trip DTC is detected, go to "Diagnostic Procedure" below.
Overall Function Check
Use this procedure to check the overall function of the rear heated oxygen sensor circuit. During this check, a 1st trip DTC might not be confirmed.
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 95 (HO2S3 signal) and engine ground.
4. Check the voltage after 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 below 2V during this procedure.
5. If NG, go to "Diagnostic Procedure" below.
EC-HO2S3-01:
Wiring Diagram
Diagnostic Procedure Step 1 - 4:
Diagnostic Procedure Step 5 - 6:
Diagnostic Procedure
Component Inspection
HEATED OXYGEN SENSOR 3
With 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 "FUEL INJECTION" in "ACTIVE TEST" mode, and select "HO2S3 (B1)" as the monitor item with CONSULT-II.
4. Check "HO2S3 (B1)" at idle speed when adjusting "FUEL INJECTION" to ±25%.
"HO2S3 (B1)" should be above 0.48V at least once when the "FUEL INJECTION" is +25%.
"HO2S3 (B1)" should be below 0.43V 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 heated oxygen sensor, clean exhaust system threads using Heated Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
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 95 (HO2S3 signal) 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 0.48V at least once.
If the voltage is above 0.48V at step 4, step 5 is not necessary.
5. Check the voltage when revving up to 6,000 rpm under no load. Or keep vehicle idling for 10 minutes, then check the voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in D position with "OD" OFF.
The voltage should be below 0.43V 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 heated oxygen sensor, clean exhaust system threads using Heated Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.