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C0577 — Brake Pressure Sensor D Circuitopen

Generic OBD-II · all makesChassis

Code C0577 indicates an electrical open circuit detected within the brake pressure sensor D circuit. This fault prevents the anti-lock brake system from monitoring hydraulic pressure accurately in that specific channel. Consequently, the ABS and traction control systems are typically disabled until the circuit is repaired.

Symptoms

What causes it — most likely first

1. Damaged wiring harness

Wires leading to the brake hydraulic unit may be broken, chafed, or corroded due to vibration and exposure.

2. Poor electrical connection

The connector at the pressure sensor or control module may be loose, oxidized, or pushed out.

3. Failed brake pressure sensor

The internal sensing element within the pressure sensor circuit has failed open.

4. Blown system fuse

A fuse supplying power to the brake control circuit may have blown, causing an open circuit condition.

5. Internal hydraulic unit fault

If the sensor is integrated, the internal circuitry of the hydraulic control unit may be damaged.

6. Faulty Electronic Brake Control Module

Internal failure of the EBCM is possible but statistically rare compared to wiring or sensor faults.

How it's diagnosed

  1. Perform a visual inspection of the wiring harness and connectors at the ABS hydraulic unit.
  2. Check all relevant fuses for the brake control system to ensure power is present.
  3. Disconnect the sensor connector and measure resistance across the circuit terminals.
  4. Verify reference voltage and ground signals at the sensor connector using a multimeter.
  5. Repair any open wiring or replace the pressure sensor if it fails resistance tests.
  6. Clear the code and perform a road test to confirm the warning light does not return.

Code facts & related codes

SystemChassis
StandardizationSAE generic — identical on every make

Frequently asked

Is it safe to drive with code C0577?

The vehicle will brake normally, but ABS and traction control will not function, increasing risk during emergency stops or slippery conditions.

Does this code mean I need a new brake computer?

No, module failure is uncommon; this code is usually caused by wiring issues or a failed sensor, not the control module itself.

Can the pressure sensor be replaced separately?

This depends on the vehicle design; some allow separate sensor replacement while others require the entire hydraulic unit assembly.

Will the code clear itself after a few drives?

No, an open circuit is a hard fault that will persist until the electrical connection is restored or the component is replaced.