Internal Mode Switch
WARNING: This page is about a different car, the 2003 Cadillac Seville and 2003 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
Individual component testing is not available from manufacturer. A malfunction in Internal Mode Switch (IMS) circuit can set a DTC. For testing procedures and specifications, perform appropriate diagnostic test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 4.6L DEVILLE & SEVILLE article.