Engine Controls - Sensor Operating Range Specifications: Introduction: Notes
Sensor operating range information can help determine if a sensor is out of calibration. An out-of-calibration sensor may not set a diagnostic trouble code, but it may cause driveability problems.
NOTE:
Perform all voltage tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Using an oscilloscope may provide better test results on some sensors. For oscilloscope waveforms and ECM terminal identification, see PIN VOLTAGE CHARTS
article.