P0573
Brake Switch "A" Circuit High
- Severity
- Medium
- Driving
- Drivable — book it in
The brake switch "A" signal is stuck high - typically shorted to voltage or an open circuit. The module gets the same answer whether or not you are braking, so cruise control, the shift interlock and the torque converter clutch will all behave unpredictably.
Possible causes
- CommonMisadjusted or failed brake pedal switch
- CommonWorn or broken striker on the pedal bracket
- CommonWiring or connector fault in the footwell
- PossibleBlown brake light fuse
- PossibleAftermarket alarm or cruise control spliced into the circuit
What you might notice
- Brake lights stuck on or not working
- Cannot shift out of park
- Cruise control will not engage or will not cancel
- Stop-start system disabled
- Check engine light on
What to check, in order
- Unplug the switch and check whether the high reading persists at the harness.
- Look at the brake lights. Working brake lights that go off when the pedal is released eliminate most of this without any tools.
- Check the switch adjustment at the pedal - these are adjustable and drift as the plastic striker wears.
- Watch the brake switch state on the live data screen while someone presses the pedal.
- Inspect the connector in the footwell, where feet catch it.
- Ask whether an aftermarket alarm or cruise control was fitted.
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
Vehicle speed control, idle control and auxiliary inputs
P0500P0501P0502P0503P0504P0505P0506P0507P0508P0509P0510P0511P0512P0513P0514P0515P0516P0517P0518P0519P0520P0521P0522P0523P0524P0525P0526P0527P0528P0529P0530P0531P0532P0533P0534P0535P0536P0537P0538P0539P0540P0541P0542P0543P0544P0545P0546P0547P0548P0549P0550P0551P0552P0553P0554P0555P0556P0557P0558P0559P0560P0561P0562P0563P0564P0565P0566P0567P0568P0569P0570P0571P0572P0573P0574P0575P0576P0577P0578P0579P0580P0581P0582P0583P0584P0585P0586P0587P0588P0589P0590P0591P0592P0593P0594P0595P0596P0597P0598P0599