P0573
Brake Switch A Circuit High
Cruise control / brake switch
Generic OBD-II
Low
What it means
P0573 means the ECM/PCM sees the brake-switch A signal stuck high (as if the brake were always pressed, or the signal shorted to voltage). The brake switch tells the computer when you're braking, so cruise control typically stops working and transmission lockup may behave oddly. Braking itself is not affected — this is a signalling fault, usually a misadjusted switch or a wiring problem.
Low
Can I keep driving? Safe to drive — the main effect is that cruise control won't work; braking itself is unaffected.
Common symptoms
What you'll notice
- Cruise control won't engage or drops out
- Check-engine light on
- Possible harsh or delayed torque-converter lockup / shift behaviour
- Brake-light or brake-switch related warning in some vehicles
Common causes
Most likely first
- Misadjusted or faulty brake-light switch at the pedalLikely
- Corroded or damaged connector or wiring in the brake-switch circuitCommon
- Short to voltage on the brake-switch signal lineCommon
- ECM/PCM fault (rare)Less often
How to diagnose & fix
Work through it in order
- Check and adjust the brake-pedal switch — many P0573 cases are just a switch out of position.
- Inspect the switch connector and wiring for corrosion, chafing, or a short to power.
- With a scan tool, watch the brake-switch state while pressing the pedal; a stuck 'high' reading confirms the fault.
- Replace the brake switch if it doesn't toggle correctly, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0573?+
Yes. Your brakes work normally — the code mainly disables cruise control and may affect transmission lockup. Fix it to restore cruise and clear the light.
Can I just clear P0573?+
It'll return until the switch or wiring is corrected. Clear it after adjusting or replacing the brake switch to confirm the repair.
Related codes
Often seen with P0573
Read & clear P0573 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX