The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sensor. The sensor element of the A/F sensor 1 is composed an electrode layer, which transports ions. It has a heater in the element.
The sensor is capable of precise measurement lambda= 1, but also in the lean and rich range. Together with its control electronics, the sensor outputs a clear, continuous signal throughout a wide lambda range.
The exhaust gas components diffuse via the diffusion layer at the sensor cell. An electrode layer is applied voltage, and this current relative oxygen density in lean. Also this current relative hydrocarbon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this electrode layer of current. In addition, a heater is integrated in the sensor to ensure the required operating temperature of approximately 800°C (1,472°F) .
DTC Logic
DTC DETECTION LOGIC
To judge malfunctions, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1 signal fluctuates according to fuel feedback control.
DTC CONFIRMATION PROCEDURE 1.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:
Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.
>> GO TO 2. 2.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A
Start engine and warm it up to normal operating temperature.
Let engine idle for 2 minutes.
Check 1st trip DTC. Is 1st trip DTC detected?
YES >> Go to Diagnosis Procedure.
NO-1 >> With CONSULT-III: GO TO 3.
NO-2 >> With GST: GO TO 7. 3.CHECK AIR FUEL RATIO (A/F) SENSOR 1 FUNCTION
Start engine and warm it up to normal operating temperature.
Select "A/F SEN1 (B1)" or "A/F SEN1 (B2)" in "DATA MONITOR" mode with CONSULT-III.
Check "A/F SEN1 (B1)" or "A/F SEN1 (B2)" indication. Does the indication fluctuate around 2.2 V?
YES >> GO TO 4.
NO >> Go to Diagnosis Procedure. 4.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B-I
Select "A/F SEN1 (B1) P1276" (for DTC P0130) or "A/F SEN1 (B2) P1286" (for DTC P0150) of "A/F SEN1" in "DTC WORK SUPPORT" mode with CONSULT-III.
Touch "START".
When the following conditions are met, "TESTING" will be displayed on the CONSULT-III screen.
If "TESTING" is not displayed after 20 seconds, retry from step 2.
CAUTION: Always drive vehicle at a safe speed.
Is "TESTING" displayed on CONSULT-III screen?
YES >> GO TO 5.
NO >> Check A/F sensor 1 function again. GO TO 3. 5.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B-II
Release accelerator pedal fully.
NOTE:
Never apply brake when releasing the accelerator pedal.
Which does "TESTING" change to?
COMPLETED>>GO TO 6.
OUT OF CONDITION>>Retry DTC CONFIRMATION PROCEDURE. GO TO 4. 6.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION B-III
Touch "SELF-DIAG RESULT".
Which is displayed on CONSULT-III screen?
OK >> Inspection END
NG >> Go to Diagnosis Procedure. 7.PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION B
Perform component function check. Refer to Component Function Check.
NOTE:
Use component function check to check the overall function of the A/F 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 Diagnosis Procedure.
Component Function Check 1.PERFORM COMPONENT FUNCTION CHECK With GST
Start engine and warm it up to normal operating temperature.
Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in the suitable gear position.
Shift the selector lever to the D position (CVT) or 5th position (M/T), then release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (31 MPH) .
CAUTION: Always drive vehicle at a safe speed.
NOTE:
Never apply brake when releasing the accelerator pedal.
Repeat steps 2 and 3 for 5 times.
Stop the vehicle and turn ignition switch OFF.
Wait at least 10 seconds and restart engine.
Repeat steps 2 and 3 for 5 times.
Stop the vehicle.
Check 1st trip DTC. Is 1st trip DTC detected?
YES >> Go to Diagnosis Procedure.
NO >> Inspection END
Discard any A/F 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 A/F 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
