Well, this is one we haven't seen before. My wife said it came on (with alarm ding) when she started the engine up. After the 3rd start up it was not on, so she drove home, with apparently the braking action normal. I'm just wondering if there is anything I can check before a mechanic looks at it. Appreciate any comments. Thanks. (2001 Prius 208k miles) (Very recently - had inverter pump and struts replaced. Changed the spark plugs, cleaned throttle plate and replaced fan belt myself) Tomorrow I'll check the brake fluid level and read any codes.