P0703 on 2002 Ford F-150. Brake light work and cruise control works

Question

brake lights work, no abs light, cruise control work. Only thing is pedal sinks to floor sometimes while sitting at traffic light.

Answer 1

Brake pedal sink to the floor, you have brake problem  a hydraulic leak it can be internal of the brake master cylinder from the primary port to its secondary, You always check calipers wheel cylinder if any, brake lines for any leaks, Your might have a brake pressure switch on the master cylinder that loves to leak.