Conditioning For Sensor Testing
HINT:
Perform the operation with the engine speeds and time durations described below prior to checking the waveforms of the air fuel ratio and heated oxygen sensors. This is to activate the sensors sufficiently to obtain appropriate inspection results.
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Put the engine in Inspection Mode (Maintenance Mode).
- Start the engine and warm it up with the A/C switch and all accessories off until the engine coolant temperature stabilizes [A].
- Enter the following menus: Powertrain / Engine / Data List / A/F (O2) Sensor Voltage B1S1 and O2 Sensor Voltage B1S2.
- Run the engine at an engine speed of 2500 rpm for at least 3 minutes [B].
HINT:
During charge control, the engine speed is set at idle. Therefore, the engine speed will not increase when the accelerator pedal is depressed. In this case, perform step [B] after charge control has completed.
- While running the engine at 2500 rpm and 1500 rpm for 2 seconds, check the waveform of the air fuel ratio sensor and heated oxygen sensor using the Techstream [C].
HINT:
- If the output voltage of either the air fuel ratio sensor or heated oxygen sensor does not fluctuate, or there is a noise in the waveform of either sensor, the sensor may be malfunctioning.
- If the voltage outputs of both the sensors remain lean or rich, the air fuel ratio may be extremely lean or rich. In such a case, perform the Active Test "Control the Injection Volume for A/F Sensor" using the Techstream.
- If the Three-way Catalytic Converter (TWC) has deteriorated, the heated oxygen sensor (located behind the Three-way Catalytic Converter [TWC]) output voltage fluctuates up and down frequently, even under normal driving conditions (active air fuel ratio control is not performed).