Air Fuel Ratio Sensor

1UR-FSE ENGINE CONTROL SYSTEM: AIR FUEL RATIO SENSOR: ON-VEHICLE INSPECTION

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:





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 A/F CONTROL (Control the Injection Volume for A/F sensor) function can help to determine whether the Air-Fuel Ratio (A/F) sensor, Heated Oxygen (HO2) sensor and other potential trouble areas are malfunctioning.
The following instructions describe how to conduct the A/F CONTROL (Control the Injection Volume for A/F sensor) operation using the Techstream.

1 Connect the Techstream to the DLC3.
2 Start the engine and turn the tester ON.
3 Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
4 On the tester, enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F sensor.
5 Perform the Active Test operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).
6 Monitor the output voltages of the A/F and HO2 sensors (AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2 S2) displayed on the tester.
HINT:
- The A/F CONTROL (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.





NOTE: The Air-Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen (HO2) sensor has a maximum output delay of approximately 20 seconds.





- Following the A/F CONTROL or Control the Injection Volume for A/F sensor procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 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.