DTC P0571: Brake Switch Circuit - Malfunction: Notes
WARNING: This page is about a different car, the 2003 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
When testing brake switch circuit, wire color changes between noise filter and brake switch. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS
article in ELECTRICAL. Wire colors given in procedure are from wire harness connector "F4-02" at noise filter.