Fault Family System: Powertrain (P-Codes) 7 SAE Codes

Brake Switch Circuit

Diagnostic & Technical Explanation

Code P0504 (Brake Switch A/B Correlation) sets when the ECM/TCM sees an implausible signal, an open/shorted circuit, or a disagreement between the two redundant brake pedal switches used to signal brake-pedal application for cruise cancel, torque converter clutch release, and stop lamps. The dominant causes are a maladjusted or worn brake light switch, a switch plunger not being contacted by the pedal arm, or corroded/chafed wiring at the pedal bracket connector.

These 7 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 7 times.

Codes in this family (7)

Code	Definition	Repair coverage
P0504	Brake Switch A/B Correlation	4 ranked fixes
P0571	Brake Switch A Circuit	4 ranked fixes
P0572	Brake Switch A Circuit Low	4 ranked fixes
P0573	Brake Switch A Circuit High	4 ranked fixes
P0703	Brake Switch B Circuit	4 ranked fixes
P0719	Brake Switch B Circuit Low	4 ranked fixes
P0724	Brake Switch B Circuit High	4 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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