C0571Brake Pressure Sensor C Circuit Low
- Generic OBD-II code · Chassis
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- Brake pressure sensor C is an additional hydraulic pressure sensor whose job depends on the brake system; each maker assigns the letter itself. GM uses C0571 in three variants. In the 2016–2019 hybrid brake control modules it is master cylinder pressure sensor 1, set when the signal line shows no voltage difference to ground for 0.1 s. In a 2019 EBCM with integrated booster it is the secondary circuit pressure sensor, set below 4.61 % of its supply within 100 ms. In the 2023 and 2025 tables a SENT master cylinder sensor pinned at its minimum of −1480 kPa for 0.96 s sets it. GM rates every variant Type A, MIL after one trip. ABS, stability control and regenerative blending are then restricted.
- What you may notice
- Check engine light together with ABS or stability warning (GM)
- Regenerative braking or brake assist reduced, pedal feel changed
- Brake pressure reading on the scan tool stuck at its minimum
- Likely causes
- LikelySensor signal line shorted to ground in the harness or connector
- PossibleSensor supply missing, so the output stays at its lowest value
- PossibleDefective pressure sensor, often integrated in the hydraulic or brake module
- Repair
- Hard · Usually a job for a workshop.Typical cost: €60 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.