Does the Garmin GPS 400 contain the same annunciators/switches that the GNS 430 has?
No. Since the Garmin GPS 400 is the GPS only version of the GNS 430 GPS/Nav/Comm, it only contains the annunciators for message, waypoint, Auto (GPS AUTO mode of operation), OBS (GPS OBS mode of operation), terminal, approach, and integrity (for position error). Since the GPS 400 does not contain the VOR/LOC/Glideslope portion of the GNS-430, the CDI source select button is omitted as well as the VLOC/GPS annunciator.