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 the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1 signal is not inordinately low.
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 10.5 V at idle.
>> GO TO 2. 2.CHECK A/F SENSOR 1 FUNCTION With CONSULT-III
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. With GST
Follow the procedure "With CONSULT-III" above.
Is the indication constantly approx. 0 V?
YES >> Go to Diagnosis Procedure.
NO >> GO TO 3. 3.PERFORM DTC CONFIRMATION PROCEDURE With CONSULT-III
Turn ignition switch OFF, wait at least 10 seconds.
Turn ignition switch ON.
Turn ignition switch OFF, wait at least 10 seconds and then restart engine.
Drive and accelerate vehicle to more than 40 km/h (25 MPH) within 20 seconds after restarting engine.
CAUTION: Always drive vehicle at a safe speed.
Maintain the following conditions for approximately 20 consecutive seconds.
NOTE:
Keep the accelerator pedal as steady as possible during cruising.
If this procedure is not completed within 1 minute after restarting engine at step 1, return to step 1.
Check 1st trip DTC. With GST
Follow the procedure "With CONSULT-III" above.
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
