Scan Tool Data Definitions

WARNING: This page is about a different car, the 2005 GMC Canyon and 2005 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.

AC Low Side Pressure: The scan tool displays 0-3450 kPa (0-500 psi). The voltage applied to the powertrain control module (PCM) input from the A/C refrigerant pressure sensor is converted to a pressure value.
A/C Relay Command: The scan tool displays On/Off. The scan tool displays the control decision for the compressor clutch relay output as determined by the PCM.
A/C Request: The scan tool displays Yes/No. Yes is displayed when the body control module (BCM) receives an input from the HVAC control assembly for an A/C request. No is displayed when there is no A/C request.
A/C Request Signal: The scan tool displays Yes/No. The scan tool displays Yes when the PCM receives a class 2 message from the body control module (BCM) to engage the A/C compressor clutch. The BCM receives a voltage input from the HVAC control assembly through the evaporator temperature sensor for an A/C request. The scan tool displays No when the PCM receives a class 2 message from the BCM to disengage the A/C compressor clutch.
ECT Sensor: The scan tool displays -39 to 140°C (-38 to 284°F). The voltage applied to the PCM input from the engine coolant temperature sensor is converted to a temperature value.