Scan Tool Data Definitions

Scan Tool Data Definitions
Check Coolant Temperature: The scan tool displays On/Off. The state of the check coolant temperature indicator as commanded by the Instrument Panel Cluster (IPC).
Check Engine Temperature: The scan tool displays On/Off. The state of the check engine temperature as commanded by the IPC.
Displayed Coolant Temperature: The scan tool displays 32 - 127°C (90 - 261°F). This is the coolant temperature gage data. This data may differ from the monitored coolant temperature from the Powertrain Control Module (PCM).
ECT: The scan tool displays -40°C to +151°C (-40°F to +304°F). The Engine Coolant Temperature (ECT) sensor is mounted in the coolant stream. The PCM applies 5 volts to the ECT sensor circuit. The sensor is a thermistor, which changes internal resistance as temperature changes. When the sensor is cold/ internal resistance high, the PCM monitors a high signal voltage and interprets it as a cold engine. As the sensor warms/internal resistance decreases, the voltage signal decreases and the PCM interprets the lower voltage as a warm engine.
Low Coolant: The scan tool displays On/Off. The state of the low coolant as commanded by the IPC. The coolant level switch signal is low.
Monitored Coolant Temperature: The scan tool displays 40 - 215°C (40 - 419°F). This is the PCM monitored coolant temperature data as provided to the IPC.