On Saturday, January 27, 2018 at 4:36:10 PM UTC-10, wrote:
> I was perusing a dashboard wiring diagram for my jalopy, and noticed that
> the brake fail lamp connects not only to the master cylinder switch
> and lamp check relay, but also to the ECU. Would this be so that the ECU
> would limit the speed of the car if brakes died?

My guess is that the master cylinder sensor is connected to the ECU so that it can turn on the warning lamps. My guess is that the ECU turns on allor most of the warning lamps.