Code P106, Stoplight Switch Input Circuit Problem: Notes
WARNING: This page is about a different car, the 1995 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
This test functions on the assumption that a sudden decrease in wheel speed on the non-drive wheel is caused by a brake application. Non-drive wheel speed and stoplight switch status are supplied to PCM through the serial data from Electronic Brake and Traction Control Module (EBTCM).