Drivers first notice the problem through the vehicle’s warning system. The ABS or brake‑control indicator lamp lights up, often accompanied by a dashboard message such as “Brake Pressure Sensor” or “Brake System Fault.” In some models the traction‑control light also activates because the system can no longer receive reliable brake‑pressure data. The brake pedal may feel firmer or softer than normal, and the anti‑lock braking modulation can be reduced, especially during hard stops. These symptoms appear suddenly and persist until the fault is cleared.
Corrosion, damaged harnesses, or loose connector pins can break the signal path between the brake‑pressure sensor and the ABS control module. An open circuit prevents any voltage from reaching the module, while a short to ground can pull the line low, both resulting in a “circuit/open” condition.
The sensor itself contains a pressure transducer and a small electronic circuit. Internal failure—often due to fluid contamination, age‑related seal degradation, or exposure to extreme temperatures—stops the sensor from generating a voltage proportional to hydraulic pressure.
Modern ABS modules communicate with the body‑control module (BCM) and the power‑train control module (PCM) via a CAN bus. A corrupted firmware image, a failed internal driver, or a loss of CAN‑bus termination can make the module appear “offline” for the sensor circuit, triggering C0573.
Brake fluid leaks onto the sensor connector or wiring loom introduce conductive residues. Over time, fluid‑induced corrosion creates intermittent resistance, which the diagnostic scanner interprets as an open circuit.
After a major service (e.g., brake‑fluid flush or ABS component replacement), the module may require a calibration cycle. If the calibration is incomplete or the software version is mismatched to the vehicle’s VIN, the module can misinterpret a valid sensor signal as “no signal,” generating the C0573 code.
– Confirm C0573 and note any additional codes (e.g., sensor A/B faults).
– Clear the code and perform a live‑data read of the brake‑pressure sensor voltage while applying brake pressure.
– Look for frayed wires, cracked insulation, or corroded pins in the sensor harness.
– Clean connectors with electrical contact cleaner and reseat them securely.
– Using a multimeter, measure resistance between the sensor’s power, ground, and signal wires.
– Compare readings to the service‑manual specifications (typically 500–1,200 Ω for the sensor signal).
– An infinite reading indicates an open circuit; a near‑zero reading suggests a short.
– Disconnect the sensor and apply brake pressure; the ABS module should register a loss of signal and log a “sensor open” condition.
– If the module still reports a fault with the sensor removed, the problem lies in the module or wiring rather than the sensor itself.
– Perform a “module handshake” test via the scanner.
– Verify that the ABS module acknowledges requests and returns data for other sensors (wheel‑speed, yaw‑rate).
– Communication errors point to a module‑level fault or bus‑termination issue.
– Replace damaged harness sections, repair broken pins, or apply heat‑shrink tubing to protect repaired splices.
– Re‑test the circuit; if the code clears and does not return, the repair is complete.
– If the wiring is sound but the code persists, reflash the module with the latest software version using the scanner’s programming function.
– Run the ABS self‑diagnostic and perform a brake‑pressure calibration cycle as outlined in the service manual.
– When the ABS control module fails internal diagnostics or continues to report a circuit/open despite repaired wiring and successful re‑programming, replacement is warranted.
– Cost estimate: OEM‑equivalent ABS modules range from $800‑$1,200 for the part; labor typically adds $200‑$300.
– Flagship One solution: Flagship One supplies VIN‑matched ABS control modules pre‑programmed to your vehicle’s specifications. Their plug‑and‑drive units include a limited‑time warranty and eliminate the need for dealer‑only re‑flash procedures.
Service Recommendation: Most issues related to this fault are diagnosed and corrected through inspection, wiring repair, and calibration rather than module replacement. For modules not typically replaced through aftermarket suppliers, diagnosis and repair should be performed by a certified automotive technician with access to factory service information and tooling.