Low Coolant Level: The scan tool displays Yes/No. The scan tool displays Yes when
the PCM or ECM detects the engine coolant level switch is closed, indicating
a low engine coolant level condition.
ECT Sensor: 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 or ECM 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 or ECM 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 or ECM interprets the lower voltage as a warm
engine.
Reduced Engine Power: The scan tool displays Yes or No. Yes indicates that the ECM has
enabled reduced power mode due to high engine coolant temperature. The ECM
will alternately disable 2 groups of 4 injectors in an attempt
to reduce the engine coolant temperature.