Conditioning For Sensor Testing
Perform the operation with the engine speeds and time durations described below prior to checking the waveforms of the A/F and HO2 sensors. This is performed in order to heat the sensors sufficiently to obtain the appropriate inspection results.
- Connect the Techstream to the DLC3 [A].
- Start the engine and warm it up with all the accessories switched off, until the engine coolant temperature stabilizes [B].
- Run the engine at an engine speed of between 2500 rpm and 3000 rpm for at least 3 minutes [C].
- While running the engine at 3000 rpm and 2000 rpm for 2 seconds, check the waveforms of the air fuel ratio and heated oxygen sensors using the Techstream [D].
HINT:
- If either of the voltage outputs of the air fuel ratio or heated oxygen sensor does not fluctuate, or either of the sensors makes a noise, 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 cases, enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor.
- If the three-way catalytic converter has deteriorated, the heated oxygen sensor (located behind the three-way catalytic converter) voltage output fluctuates up and down frequently, even under normal driving conditions (active air fuel ratio control is not performed).