Final answer:
The coldest possible reading on a scan tool temperature sensor likely indicates that the temperature sensor is malfunctioning. The gasoline gauge reading remains consistent regardless of temperature, indicating fuel level without being influenced by weather conditions.
Step-by-step explanation:
When using a scan tool, if the temperature sensor has its coldest possible reading, it could mean several things. However, based on the options provided, the most likely answer is that the temperature sensor is malfunctioning. Sensors can fail or provide inaccurate readings if they're damaged or have poor electrical connections. An abnormally low temperature reading when you know the engine is warmed up is a typical sign of a sensor issue. It is less likely that the engine is overheating, the coolant level is low, or the scan tool is not working properly, as these scenarios typically produce different symptoms or readings on the scan tool.
Regarding the CHECK YOUR UNDERSTANDING 1.1 question, the gasoline gauge reading does not depend on the temperature; it displays the level of gasoline in the tank regardless of the weather being cold or hot. Therefore, the temperature does not matter in terms of indicating more or less gasoline based on the gauge's reading.