What are the two basic types of direct TPMS sensors?

The two basic types of direct Tire Pressure Monitoring System (TPMS) sensors are indeed stem-mounted and banded. Stem-mounted sensors are attached directly to the valve stem of the tire, which allows for easy installation and maintenance. This type generally provides more accurate pressure readings since it is placed directly in the tire.

Banded sensors, on the other hand, are mounted on the tire's rim using a band. This design is particularly useful for certain types of wheels that do not have a valve stem or for aftermarket wheels that may not accommodate stem-mounted sensors effectively.

The significance of knowing these types lies in their roles in monitoring tire pressure accurately and helping to ensure vehicle safety and performance. Understanding the differences and applications of these sensors is crucial for proper tire maintenance and for diagnosing any issues related to the TPMS in various vehicle models.