HomeTrouble CodesP0724

P0724 — Brake Switch B Circuit High

Generic OBD-II · all makesPowertrain (engine & transmission)

The engine computer has detected that the voltage signal from the second brake switch (Switch B) is higher than the expected operating range. This typically indicates an open circuit or a failure within the switch assembly.

Symptoms

What causes it — most likely first

1. Faulty Brake Switch B

The internal contacts of the switch have failed or worn out, causing an open circuit.

2. Damaged Wiring

Frayed, broken, or pinched wires in the brake switch circuit causing a signal interruption.

3. Corroded Connectors

Corrosion or loose fitment at the switch connector pins creating high resistance or an open circuit.

4. Broken Pedal Stop

A broken plastic pedal stop may prevent the switch from being depressed correctly, altering the circuit state.

5. PCM Internal Failure

An internal fault in the powertrain control module's signal processing circuit.

How it's diagnosed

  1. Scan for all present DTCs to determine if multiple brake switches or related sensors are reporting faults.
  2. Visually inspect the brake pedal area for a broken pedal stop or loose switch mounting.
  3. Inspect the wiring harness and connectors for physical damage or corrosion.
  4. Perform a continuity test on the brake switch using a digital multimeter to verify it toggles correctly.
  5. Measure the voltage at the switch connector to ensure the PCM is providing the correct reference voltage.
  6. Perform a pin-out test at the PCM to rule out wiring breaks between the switch and the computer.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make

Frequently asked

Will this code affect my ability to stop the vehicle?

No, the mechanical braking system operates independently of the electronic switches; however, electronic safety features like cruise control may be disabled.

Why are there two different brake switches?

Many vehicles use redundant switches to ensure that critical systems, such as the shift interlock and cruise control, have a fail-safe method of detecting brake application.

Should I replace the PCM if I have this code?

No. P0724 is almost always caused by a failed switch or wiring issue. Replacing the PCM without first verifying the integrity of the switch and wiring is usually incorrect.