P0504 Code - Brake Switch Circuit 'A' / 'B' Correlation
Quick Answer
In addition to turning on the stop lamp, the stop lamp switch signals are used for a variety of engine, transmission, and suspension functions as well as being an input for diagnostic checks. Common causes include Faulty Brake Lamp Switch, Blown Brake Lamp Bulb, Blown Brake Lamp Fuse. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0504 indicates Brake Switch Circuit 'A' / 'B' Correlation.
- Common causes
- Common causes include Faulty Brake Lamp Switch, Blown Brake Lamp Bulb, Blown Brake Lamp Fuse.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0504 Description
The Engine Control Module (ECM) analyzes these signal outputs to detect malfunctions in the stop lamp switch.
What are the Possible Causes of the DTC P0504?
- Faulty Brake Lamp Switch
- Blown Brake Lamp Bulb
- Blown Brake Lamp Fuse
- Brake Lamp Switch harness open or shorted
- Brake Lamp Switch circuit poor electrical connection
How to Fix the DTC P0504?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0504 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Makes
- P0504 Buick — TCC Brake Switch/Cruise Control Input Mismatch
- P0504 Cadillac — TCC Brake Switch/Cruise Control Input Mismatch
- P0504 Chevrolet — TCC Brake Switch/Cruise Control Input Mismatch
- P0504 Chrysler — Brake Switch Circuit 'A' / 'B' Correlation
- P0504 Dodge — Brake Switch Circuit 'A' / 'B' Correlation
- P0504 Ford — Brake Switch Circuit 'A' / 'B' Correlation
- P0504 GMC — TCC Brake Switch/Cruise Control Input Mismatch
- P0504 Hyundai — Brake Switch 'A' / 'B' Correlation
- P0504 Jeep — Brake Switch Circuit 'A' / 'B' Correlation
- P0504 KIA — Brake Switch 'A' / 'B' Correlation
- P0504 Lexus — Brake Switch Circuit 'A' / 'B' Correlation
- P0504 Lincoln — Brake Switch Circuit 'A' / 'B' Correlation
- P0504 Mazda — Brake Switch Circuit 'A' / 'B' Correlation
- P0504 Mercury — Brake Switch Circuit 'A' / 'B' Correlation
- P0504 Scion — Brake Switch Circuit 'A' / 'B' Correlation
- P0504 Suzuki — Brake Switch Circuit 1-2 Correlation
- P0504 Toyota — Brake Switch Circuit 'A' / 'B' Correlation
Frequently Asked Questions about P0504 Code
No Frequently Asked Questions about P0504 Code found.
Discuss the causes and fixes for P0504 OBDII Code
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I just got this code on 2004 Toyota Sienna. It burned brake light fuse instantly and when i turn running light also all brake lights went on. It all went down to faulty stop light bulb that caused short circuit.
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