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 A/F signal computed by ECM from the A/F sensor 1 signal is monitored so it will not shift to LEAN side or RICH side.
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
Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected? Is it difficult to start engine?
YES >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to See: P0171, "DTC See: P0172.
NO >> GO TO 6. 6.CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
Disconnect A/F sensor 1 harness connector.
Turn ignition switch ON.
Check the voltage between A/F sensor 1 harness connector and ground.
Is the Inspection result normal?
YES >> GO TO 8.
NO >> GO TO 7. 7.DETECT MALFUNCTIONING PART
Check the following.
IPDM E/R harness connector F10
15 A fuse (No. 37)
Harness for open or short between A/F sensor 1 and IPDM E/R >> Repair or replace harness or connectors.
8.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
Turn ignition switch OFF.
Disconnect ECM harness connector.
Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector and ground.
Also check harness for short to power. Is the Inspection result normal?
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 ThreadCleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant