Note On INTERMITTENTS

WARNING: This page is about a different car, the 1992 Oldsmobile Toronado. However, it is still accessible from the selected car via links, so may be relevant.

If an intermittent Code B121 is being set, manipulate related wiring. When BCM BI82 displays change-of-state, an "X" will be indicated. Check circuit for an intermittent open or short.

Fig 1: Code B121, Schematic, Twilight Enable Switch Ckt

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code B121, Flow Chart, Twilight Enable Switch Ckt

Courtesy of GENERAL MOTORS CORP.