Note On Intermittents
WARNING: This page is about a different car, the 1992 Cadillac Fleetwood and 1992 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
If intermittent Code F40 is being set, manipulate related wiring while observing parameter P.2.3. If failure is induced, door reading will either stop or jump to an extreme value (zero or 100 percent). This will help isolate location of malfunction.