Diagnostic article Generic OBD-II
P0724: Brake signal stays active during repeated acceleration
P0724 checks an implausibly active brake-switch indication against vehicle acceleration in this GM implementation.
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Documented application
2009 General Motors diagnostic parameter file 09OBDG06 Engine Diagnostics.pdf. Section-specific modules and calibrations; no per-code model or engine applicability established.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P0724 is the high-direction brake-switch plausibility code in GM's group 06 summary. The controller evaluates repeated acceleration while the brake indication remains active. This implementation therefore uses a relationship between operating behavior and switch state, rather than a published universal high-voltage threshold.
The active state needs operating context
The documented pattern is four increases from approximately 2 mph to 25 mph within a specified time window, with the engine running and the brake signal active. These are monitor criteria, not road-test instructions. Diagnostic equipment and the approved service procedure should be used to examine the original event safely.
The opposite P0719 strategy evaluates an inactive signal during repeated deceleration. Keeping those patterns separate helps identify whether the controller saw an input that appeared stuck active or one that failed to indicate braking.
A brake lamp check is only part of the evidence
The code does not prove a hydraulic brake problem or establish brake-system safety. It concerns the controller's brake-status information. A single correct lamp response may not demonstrate that every monitored signal path is reliable.
Preserve the brake status, speed history and companion faults. Confirm the vehicle's exact switch arrangement before testing or adjustment. Verification should show correct release and activation recognition plus completed plausibility monitoring. Erasing P0724 without checking the monitored status can leave the original disagreement unresolved.
Source and applicability
2009 General Motors diagnostic parameter file 09OBDG06 Engine Diagnostics.pdf. Section-specific modules and calibrations; no per-code model or engine applicability established. This explanation describes the documented monitor, not a universal repair procedure.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Brake Switch B Circuit High
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT