Brake light flashing 90 Surburban

Brake light flashes 9 times then repeats. Replaced master cylinder, but no help.
Any ideas would be appreciated.

Thanks

Brake light flashes 9 times then repeats. Replaced master cylinder, but no help.
Any ideas would be appreciated.

Thanks
Are you going to keep throwing parts at it otr try to figure it out with some proper testing?
What size Surburban and 2W or 4W anti lock brakes.

Confirm flashing code 9 by grounding pin H and reading codes.
Then measure voltage between pin H and A.
Post back code no and voltage reading.