A short to voltage or high resistance in the signal wire between the brake pressure sensor and the ABS module.; A faulty brake pressure sensor F that is internally shorted or has failed, sending a high voltage signal.; Corroded, loose, or damaged electrical connectors at the sensor or ABS module.; A defective ABS control module that is misinterpreting the sensor signal.; Low brake fluid level or air in the hydraulic system causing the sensor to read incorrectly.; A pinched or chafed wire harness that is contacting a power source.; A faulty ground connection for the sensor or module, causing a reference voltage shift.

DTC codes / C05xx · Brakes, steering and suspension / C05C7

C05C7Brake Pressure Sensor F Circuit High

Q: What does code C05C7 mean?

Brake Pressure Sensor F Circuit High. The C05C7 code indicates that the anti-lock brake system (ABS) control module has detected an abnormally high voltage or signal on the electrical circuit for the brake pressure sensor F. The sensor itself converts hydraulic brake pressure into an electrical signal, and the module expects that signal to stay within a specific range; a high reading means the circuit is either receiving too much voltage or the sensor is reporting pressure that is higher than physically possible.

The C05C7 code indicates that the anti-lock brake system (ABS) control module has detected an abnormally high voltage or signal on the electrical circuit for the brake pressure sensor F. The sensor itself converts hydraulic brake pressure into an electrical signal, and the module expects that signal to stay within a specific range; a high reading means the circuit is either receiving too much voltage or the sensor is reporting pressure that is higher than physically possible.

SystemChassis

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaBrakes, steering and suspension

Symptoms you may notice

The ABS warning light is illuminated on the dashboard, often accompanied by the traction control and stability control lights.
The brake pedal may feel unusually firm or require more effort to stop the vehicle.
The ABS system may be disabled, leading to wheel lockup during hard braking.
Some vehicles may enter a reduced-power limp mode or limit vehicle speed.
Often no symptoms besides the warning light, especially if the fault is intermittent.
The cruise control may become inoperative if it relies on brake pressure data.

Common causes, most likely first

A short to voltage or high resistance in the signal wire between the brake pressure sensor and the ABS module.
A faulty brake pressure sensor F that is internally shorted or has failed, sending a high voltage signal.
Corroded, loose, or damaged electrical connectors at the sensor or ABS module.
A defective ABS control module that is misinterpreting the sensor signal.
Low brake fluid level or air in the hydraulic system causing the sensor to read incorrectly.
A pinched or chafed wire harness that is contacting a power source.
A faulty ground connection for the sensor or module, causing a reference voltage shift.

How to diagnose and fix it

Verify the code with a scan tool and check for any related codes in the ABS module.
Inspect the brake fluid level and condition, and bleed the brakes if air is suspected.
Visually inspect the brake pressure sensor and its wiring for damage, corrosion, or loose connections.
Disconnect the sensor and measure the reference voltage and ground at the connector with a multimeter; compare to manufacturer specifications.
Check the signal wire for a short to voltage by measuring voltage with the sensor disconnected and the key on.
If the wiring and connectors are good, test the sensor with a known-good unit or use a pressure gauge to compare actual hydraulic pressure to the sensor reading.
If the sensor and wiring check out, diagnose the ABS module for internal faults, including checking powers and grounds.

Common Oversights When Diagnosing C05C7

A low brake fluid level or air trapped in the hydraulic system can cause the brake pressure sensor to output a high signal, so always check the fluid and bleed the brakes before condemning the sensor.
The code can be set intermittently by a chafed wire that only shorts to voltage when the engine moves under load, so a wiggle test of the harness while monitoring sensor data is essential.
Some vehicles use a shared reference voltage for multiple sensors; a fault in another sensor on the same circuit can pull the reference voltage high and trigger C05C7.
After replacing the brake pressure sensor, the ABS module may require a calibration or relearn procedure, and skipping this step can leave the code stored or cause poor brake performance.
A failing ABS module can mimic a sensor circuit high fault, so do not replace the sensor without first verifying the module's ability to read and process the signal correctly.

Can I keep driving with C05C7?

Because this fault can disable the anti-lock braking system and affect overall braking performance, you should avoid driving the vehicle until the issue is diagnosed and repaired. If you must move the car a short distance, drive at low speed and leave extra following distance, and be prepared for a firmer brake pedal or reduced stopping ability.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.