Scan Tool Data Definitions

Scan Tool Data Definitions

Displayed Coolant Temp
The scan tool displays -39°C to +140°C (-38°F to +284°F). This is the actual indication of the displayed coolant temperature.

ECT
The scan tool displays -39°C to +140°C (-38°F to +284°F). The engine coolant temperature (ECT) sensor is mounted in the coolant stream. The powertrain control module (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.

High Speed Fan Relay
The scan tool displays On and Off. It represents the commanded state of the high speed cooling fan relay as commanded by the PCM.

Low Speed Fan Relay
The scan tool displays On and Off. It represents the commanded state of the low speed cooling fan relay as commanded by the PCM.

Monitored Coolant Temp
The scan tool displays -39°C to +140°C (-38°F to +284°F). This is the actual coolant temperature as received from the powertrain control module (PCM).