Hey Scotty,

The brake light comes on after my truck heats up, especially in hot summer days. This was intermittent, but now it goes on regardless of temp and within 5 min of start up.  I have a C1223 and a C1247 error code.  The C1223 is an abs malfunction code and the C1247 is a stoke sensor.  I have seen on the internet, various forums discussion similar conditions and dealer horror stories of replacing parts and not fixing this.  I did read one person that bought and installed a salvaged replacement booster and master cylinder that fixed this.  I believe the actual stroke sensor is in the brake booster, but is not a serviceable part, so this fix sort of makes sense, if it is just a sensor issue. 

The brakes work normally still and I have had this light and the stroke sensor issue for 30k miles now with no braking issues. I have been getting the car inspected on "cool" June morning, but the light is on all the time now, so I have until next June to finally sort this out.

Any suggestions on this before I replace this booster, hoping it corrects this issue.  Thanks!