Conditioning For Sensor Testing
HINT:
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 in order to activate 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 between 2500 RPM and 3000 RPM for at least 3 minutes [C].
- While running the engine at 3000 RPM for 2 seconds, and then 2000 RPM for 2 seconds, check the waveforms of the A/F and HO2 sensors using the Techstream.
HINT:
- If the voltage output of either the Air-Fuel Ratio (A/F) or Heated Oxygen (HO2) 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, perform Control the Injection Volume for A/F sensor using the Techstream.
- If the Three-Way Catalytic Converter (TWC) has deteriorated, the HO2 sensor (located behind the TWC) voltage output fluctuates up and down frequently, even under normal driving conditions (active air-fuel ratio control is not performed).