Tire Pressure Monitoring System (TPMS) Module
WARNING: This page is about a different car, the 2008 Ford RV Cutaway, 2008 Ford Econoline, 2008 Ford E450 Super Duty, and 2008 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The VSM contains the TPMS functionality. Refer to Tire Pressure Monitoring System in Diagnosis and Testing for TPMS fault diagnosis and repair.
The VSM compares the information of each tire pressure sensor transmission against a pressure limit. If the VSM determines that the tire pressure has fallen below the low limit, the VSM communicates this to the IC on the vehicle communication bus.