Peugeot 405 Question

Well gee, at a guess, i think it might be you should stop :)

Did any other lights come on at the same time? Oil light perhaps?

Usually comes on with high coolant temperature, or low oil pressure. Check your water & oil level.

Do you get a "stop" light with ignition key prior to start up. It should illuminate- mine does not (although it can come at start times on odd occasions so connection and light still work. Maybe earth fault or contacts require a clean.) Red light should go out when engine started. Other lights prior to start up should be glow plugs, battery, oil light/handbrake light., high coolant temp , Some models have water in diesel light, ABS, engine oil level gauge and diagnostic function.

If you do have a serious fault then that is usual for the red light to flash on and off with a clicking noise. Reasons are oil pressure low/coolant temp high/loss of coolant.(may be others like brake fluid but do not know for sure). The fault condition should also be illuminated on the dash.

I would check out oil levels, coolant levels, battery condition (including leads are not loose), brake fluid level., brake pad wear.etc.

Give a follow up on progress as it will be of assistance to other Peugeot owners - other models have this "feature"

Could be that your brake fluid level is a little low.

check your brake fluid level and if ok check brake light switch on top of pedal for faulty switch.