Small donut spare set off brake light?
 

Got a flat last Tuesday, so throw on the small joke tire that passes for a spare.
Wednesday morning I drive to the tire shop to get the flat tire fixed and on the way there the brake light on the dash goes off.
So I am all *&^$&% great I got a bad tire AND now I need a brake job ($$$)
Pretty sure I had the spare installed correctly, lugs were tight and caliper was clear.
I am thinking maybe the ABS sensed the tiny tire and that set off the brake light? Pretty sure the tiny spare is not as tall as the regular tire so would spin at a different RPM.

Leaving the tire shop the brake light was off and hasn't come on since.

Very possible, measure the height of the spare vs. Stock, I'd it's more than an inch is day that's what it was

ABS - what's that ('79 SC guy here).

A friend has more woes than that. His BMW automatic wouldn't shift gear because one wheel had less tread than the other and the car thought it must be going around a corner.

Scary thing is I see people on the freeway with these 'donut' tires. :eek:

I got the flat on the way home late at night, I was white knuckling it to the tire shop the next morning on surface streets.

1)- ABS light or Worn brake pad light-

2)- did you knock the pad wear sensor loose when putting wheel on?

Don't think so but it was dark when I changed the tire and I suppose the guy at the tire store may have put it back and didn't think to tell me.