P0724
Brake Switch "B" Circuit High
- Severity
- Medium
- Driving
- Drivable — book it in
The brake switch "B" signal is stuck high - typically shorted to voltage, or the switch is stuck in the other state. The module cannot tell whether the brake pedal is pressed, so anything that depends on that will misbehave: the shift interlock, cruise control, and the torque converter clutch that should release when you brake.
Possible causes
- CommonFailed or misadjusted brake pedal switch
- CommonWiring shorted or open between the switch and the module
- PossibleCorroded connector at the switch
- PossibleBlown fuse on the brake light circuit
- PossibleAftermarket wiring spliced into the brake switch circuit
What you might notice
- Brake lights stuck on or not working
- Cannot shift out of park
- Cruise control unavailable or not cancelling
- Check engine light on
What to check, in order
- Look at the brake lights first. A signal stuck high usually shows there before it shows anywhere else.
- Watch the brake switch state on the live data screen while the pedal is pressed and released. A reading that never changes confirms the fault.
- Unplug the switch and check whether the high reading persists at the harness. If it does, the fault is in the wiring rather than the switch.
- Check the switch adjustment before condemning it - a switch that is simply not being reached by the pedal reads exactly like a failed one.
- Brake lights stuck on will flatten the battery overnight and will confuse drivers behind you. Fix this promptly even though the car drives.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Transmission
P0700P0701P0702P0703P0704P0705P0706P0707P0708P0709P0710P0711P0712P0713P0714P0715P0716P0717P0718P0719P0720P0721P0722P0723P0724P0725P0726P0727P0728P0729P0730P0731P0732P0733P0734P0735P0736P0737P0738P0739P0740P0741P0742P0743P0744P0745P0746P0747P0748P0749P0750P0751P0752P0753P0754P0755P0756P0757P0758P0759P0760P0761P0762P0763P0764P0765P0766P0767P0768P0769P0770P0771P0772P0773P0774P0775P0776P0777P0778P0779P0780P0781P0782P0783P0784P0785P0786P0787P0788P0789P0790P0791P0792P0793P0794P0795P0796P0797P0798P0799