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.
- (a) Connect the Techstream to the DLC3.
- (b) Put the engine in inspection mode. Refer to INSPECTION MODE PROCEDURE .
- (c) Warm it up with all the accessories switched OFF, until the engine coolant temperature stabilizes.
- (d) Run the engine at an engine speed of between 2000 RPM and 2500 RPM for at least 3 minutes.
- (e) While running the engine at 2500 RPM and 1500 RPM for 2 second intervals, check the waveforms of the A/F and HO2 sensors using the Techstream.
HINT:
- If the voltage output of 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 the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.
- 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).