Air Fuel Ratio Sensor

2UR-GSE ENGINE CONTROL: AIR FUEL RATIO SENSOR: ON-VEHICLE INSPECTION

1. INSPECT AIR FUEL RATIO SENSOR





(a) Disconnect the air fuel ratio sensor connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





(b) If the result is not as specified, replace the air fuel ratio sensor.

2. INSPECT AIR-FUEL RATIO COMPENSATION SYSTEM

HINT
Malfunctioning areas can be identified by performing the Control the Injection Volume for A/F sensor function provided in the Active Test. The Control the Injection Volume for A/F sensor function can help to determine whether the air-fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume for A/F sensor operation using the Techstream.

* Connect the Techstream to the DLC3.
* Start the engine and turn the Techstream ON.
* Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
* Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F sensor.
* Perform the Active Test operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).
* Monitor the output voltages of the air-fuel ratio and heated oxygen sensors (AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2 S2) displayed on the Techstream.
HINT
* The Control the Injection Volume for A/F sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
* Each sensor reacts in accordance with increases and decreases in the fuel injection volume.






NOTICE:
The air-fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.





* Following the Control the Injection Volume for air-fuel ratio sensor procedure enables technicians to check and graph the voltage outputs of both the air-fuel ratio and heated oxygen sensors.

* To display the graph, enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor / A/F Control System / AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2 S2.