P0504 on 2016-2019 Nissan Sentra (S, SV, SR, SL) — Brake Switch "A"/"B" Correlation
1 vehicles · 1 makes
Most Reported On
P0504 is an OBD-II diagnostic trouble code meaning “Brake Switch "A"/"B" Correlation.” Most vehicles use two independent brake switch signals (a normally-open and a normally-closed circuit, switch A and switch B). The PCM compares them and expects them to change state together when the brake pedal is pressed. P0504 sets when the two signals disagree (do not correlate), indicating one switch or circuit is faulty. This code is most commonly reported on 2016-2019 Nissan Sentra (S, SV, SR, SL).
Common Causes
Diagnostic Tools
To diagnose P0504, you'll need an OBD-II scanner. Here are our recommendations at every price point.
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FAQ
What does P0504 mean?
P0504 stands for "Brake Switch "A"/"B" Correlation." Most vehicles use two independent brake switch signals (a normally-open and a normally-closed circuit, switch A and switch B). The PCM compares them and expects them to change state together when the brake pedal is pressed. P0504 sets when the two signals disagree (do not correlate), indicating one switch or circuit is faulty.
What are the most common causes of P0504?
The most common causes of P0504 are: Failed brake light switch, Misadjusted brake switch (plunger gap), Wiring/connector fault on one of the two brake switch circuits, Blown brake-circuit fuse affecting one signal, Faulty PCM input. The specific cause varies by vehicle.
How much does it cost to fix P0504?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P0504?
Au7o has documented P0504 across 1 vehicle models from 1 manufacturers: Nissan.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.