Electrical and sensors

P0724 — Brake Switch B Circuit High

Severity: medium Safe to drive

What P0724 means

The engine or transmission control module monitors the brake switch (brake pedal sensor B) and compares it with what the car is doing. With P0724, the circuit voltage is too high or the circuit is open, so the signal does not make sense. This signal is used for brake lights, canceling cruise control and releasing the torque converter clutch when you brake.

Symptoms

  • Check Engine light on
  • Cruise control not working
  • Harsh or odd transmission shifting
  • Stalling or shuddering when braking to a stop (torque converter not releasing)
  • Brake lights not working or stuck on

Possible causes

  1. Failed or misadjusted brake switch
  2. Open circuit in the brake switch wiring
  3. Blown fuse on the brake switch feed
  4. Wiring shorted to positive voltage
  5. Corroded or damaged connector
  6. Faulty ECM/PCM or TCM (uncommon)

How to diagnose

  1. Scan for codes and view brake switch status in live data
  2. Check whether the brake lights work and turn off when the pedal is released
  3. Inspect the switch at the pedal, its position and connector
  4. Check the fuse for the brake switch circuit
  5. Measure voltage at the switch with the pedal pressed and released
  6. Test the wiring for opens and shorts to power
  7. Test the switch itself with a multimeter
  8. If all is good, check the control module and its connectors

Common fixes

  • Replace or properly adjust the brake switch
  • Replace the fuse after finding the cause of the overload
  • Repair the wiring or connector
  • Fix the short to positive voltage
  • Reprogram or replace the control module if confirmed faulty

Questions and answers

What does P0724 mean?

It means the brake switch B circuit is open or reading high voltage. The control module is getting an unreliable brake pedal signal.

Can I drive with P0724?

Usually yes, but cruise control and the transmission may act up. Make sure the brake lights work and repair it soon.

What most often causes P0724?

Most often it is a failed or misadjusted brake switch, a blown fuse, or damaged wiring or a connector.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.