Air Fuel Ratio Sensor (For Sensor 1)

4GR-FSE EMISSION CONTROL: AIR FUEL RATIO SENSOR (for Sensor 1): ON-VEHICLE INSPECTION

1. INSPECT AIR FUEL RATIO SENSOR (for Bank 1)

(a) Disconnect the A/F 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 sensor.

2. INSPECT AIR FUEL RATIO SENSOR (for Bank 2)

(a) Disconnect the A/F 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 sensor.

3. INSPECT AIR-FUEL RATIO COMPENSATION SYSTEM

(a) Measure the voltage between the terminals of the ECM connectors.





Standard resistance:





NOTICE:
* Connect the tester leads from the backside of the connector. The connector should not be disconnected from the ECM.
* The voltage between the terminals of the ECM is kept constant regardless of the voltage of the A/F sensor.

(b) Connect Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Select the following menu items: Powertrain / Engine and ECT / Data List / AFS B1 S1, AFS B2 S1, O2S B1 S2 and O2S B2 S2.

(e) Warm up the A/F sensor by running the engine at 2500 rpm for approximately 2 minutes.

(f) Keep the engine speed at 2500 rpm and confirm that the displays of "AFS B1 S1" and "AFS B2 S1" are as shown in the illustration.





HINT
* The illustration may slightly differ from the display on the Techstream.
* The waveform of the A/F sensor is displayed only on the Techstream.

(g) Check the displays of "O2S B1 S2" and "O2S B2 S2" with the engine speed at 2500 rpm.

Standard condition:

Displays show that each voltage fluctuates between 0 and 1 V.

NOTICE:
* Perform the check immediately after warming up the engine.
* If the voltage oscillation could not be verified, warm up the heated oxygen sensor again. If it is still not possible to verify, perform DTC check DTC Check / Clear.