DTC P0703: Brake Switch Input Malfunction & DTC P1703: Brake Switch Circuit Out Of Self-Test Range: Condition

WARNING: This page is about a different car, the 2002 Mazda 626. However, it is still accessible from the selected car via links, so may be relevant.

DTC is set when Powertrain Control Module (PCM) detects brake switch signal voltage switch from on to off, or from off to on. Possible causes are:

Brake switch malfunction.
Stop light switch noise filter.
Open circuit between STOP fuse (15-amp) and stop light switch.
Short or open circuit between stop light switch noise filter and brake switch.
Short or open circuit between stop light switch noise filter and PCM.