Toronado Models
WARNING: This page is about a different car, the 1986 Oldsmobile Toronado and 1986 Buick Riviera. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition is on and the "SYSTEM MONITOR" button is pressed, the BCM will cause the IPC and ECC to sequentially illuminate and darken all segments and lights in the clusters. This helps to determine if any bulbs or segments of the instrument clusters vacuum fluorescent display are out, or always on. Also, to give the technician more time to study, a total illumination of all segments and bulbs will occur when service diagnostics are entered.