Faulty brake pressure sensor; Damaged or corroded wiring or connector at the sensor; Open or short circuit in the sensor signal or reference voltage circuit; Contaminated or aerated brake fluid affecting sensor readings; Failed ABS control module (less common); Low brake fluid level or air in the hydraulic system

DTC codes / C02xx · Brakes, steering and suspension / C0240

C0240Brake Pressure Sensor

Q: What does code C0240 mean?

Brake Pressure Sensor. C0240 is a generic chassis code indicating a fault in the brake pressure sensor circuit, which the antilock braking system (ABS) module uses to measure hydraulic pressure applied by the driver or the stability control system. The computer has detected an abnormal signal from this sensor, such as a voltage out of range, an implausible reading, or a loss of communication with the sensor, and it has stored this code while illuminating the ABS warning light.

C0240 is a generic chassis code indicating a fault in the brake pressure sensor circuit, which the antilock braking system (ABS) module uses to measure hydraulic pressure applied by the driver or the stability control system. The computer has detected an abnormal signal from this sensor, such as a voltage out of range, an implausible reading, or a loss of communication with the sensor, and it has stored this code while illuminating the ABS warning light.

SystemChassis

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaBrakes, steering and suspension

Symptoms you may notice

ABS warning light illuminated on the dashboard
Traction control or stability control warning light also on, since these systems share the brake pressure sensor
Reduced or disabled ABS function, though normal braking usually remains
A soft or inconsistent brake pedal feel in some cases
Often no symptoms besides the warning light, with the vehicle driving normally

Common causes, most likely first

Faulty brake pressure sensor
Damaged or corroded wiring or connector at the sensor
Open or short circuit in the sensor signal or reference voltage circuit
Contaminated or aerated brake fluid affecting sensor readings
Failed ABS control module (less common)
Low brake fluid level or air in the hydraulic system

How to diagnose and fix it

Inspect the brake pressure sensor connector and wiring for corrosion, damage, or loose pins
Check brake fluid level and condition, and bleed the system if air is suspected
Use a scan tool to read live data from the brake pressure sensor and compare with a known good value or mechanical gauge
Test the sensor reference voltage and ground circuits with a multimeter
Replace the brake pressure sensor if testing confirms it is faulty
Clear the code and perform a road test to verify the repair, including ABS operation

What the brake pressure sensor code hides

A low brake fluid level or air in the hydraulic system can cause implausible pressure readings and set C0240 without any sensor fault, so always check fluid level and bleed the system before replacing parts.
Corroded or chafed wiring near the ABS module or sensor is a frequent culprit, especially on vehicles driven in salt-belt regions, and a visual inspection often reveals the problem.
The brake pressure sensor is sometimes integrated into the ABS hydraulic unit, making replacement more involved and costly, so confirm the sensor is separate before quoting a repair.
C0240 can be set by a failing ABS control module that misinterprets a good sensor signal, so don't overlook module diagnostics if the sensor and wiring test good.
After repairs, some vehicles require a scan-tool bleed procedure or calibration of the brake pressure sensor to fully restore ABS function and clear the code.

Can I keep driving with C0240?

You can usually drive the vehicle with C0240, but the ABS and stability control systems may be disabled, which reduces safety in emergency braking or slippery conditions. Avoid hard braking and slippery roads, and have the fault diagnosed promptly to restore full braking assistance.

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.