My Pro Street

C0298 Code Explained: Causes, Symptoms & Brake Pressure Sensor Performance Fixes

An OBD-II scanner displaying C0298 beside an ABS hydraulic control unit with an integrated brake pressure sensor highlighted, showing abnormal pressure readings while the ABS, brake, traction control, and StabiliTrak warning lights are illuminated.

If your scan tool displays C0298, your vehicle’s Electronic Brake Control Module (EBCM) has detected that the brake pressure sensor is reporting values outside its expected operating range. This means the module no longer trusts the brake pressure readings it uses to manage the Anti-lock Braking System (ABS), Traction Control System (TCS), and Electronic Stability Control (ESC/StabiliTrak).

The brake pressure sensor continuously monitors hydraulic brake pressure generated when you press the brake pedal. The EBCM compares this information with wheel speed sensors, brake pedal position, and vehicle speed to determine how much brake force is being applied. If the sensor reports pressure that is too high, too low, erratic, or inconsistent with other vehicle inputs, the EBCM stores C0298 and disables several advanced braking systems to protect vehicle stability.

Unlike brake switch or communication-related fault codes, C0298 is a performance code, meaning the sensor is still communicating but the information it provides doesn’t make sense based on actual driving conditions.

For additional chassis diagnostics and repair guides, visit our Complete OBD-II Trouble Code Guide:

https://my.prostreetonline.com/dtc-obdii

Quick Facts

ItemInformation
OBD-II CodeC0298
DescriptionBrake Pressure Sensor Performance
CategoryChassis (C) Codes
SystemABS / Brake Hydraulic System
Severity★★★★☆ High
Safe to Drive?Yes, but ABS and stability systems may be disabled
Common CausesFaulty brake pressure sensor, Hydraulic Control Unit failure, low brake fluid, air in brake lines, damaged wiring
Typical Repair Cost$100–1,800

What Does C0298 Mean?

The C0298 code indicates the Electronic Brake Control Module has determined that the brake pressure sensor signal is outside the expected operating range or does not correlate with other braking system inputs.

Modern braking systems rely on accurate hydraulic pressure measurements to control:

The brake pressure sensor is typically mounted within or near the Hydraulic Control Unit (HCU) and continuously reports hydraulic pressure to the EBCM.

During braking, the EBCM compares brake pressure against:

If the reported pressure doesn’t match expected values, the module determines the sensor is no longer providing reliable information and stores C0298.

Symptoms of C0298

Common symptoms include:

Some vehicles may also experience:

Common Causes

Faulty Brake Pressure Sensor

The pressure sensor itself is the most common cause of C0298.

Internal failures may include:

Hydraulic Control Unit Failure

Many manufacturers integrate the brake pressure sensor into the Hydraulic Control Unit (HCU).

Internal hydraulic or electronic failures within the HCU may require replacement of the complete assembly.

Low Brake Fluid Level

Low brake fluid can reduce hydraulic pressure and produce sensor readings outside the expected range.

Always inspect the master cylinder reservoir before replacing components.

Air in the Brake System

Air compresses much more easily than brake fluid.

Air trapped inside the hydraulic system may cause pressure readings that fluctuate unexpectedly during braking.

Brake Fluid Contamination

Contaminated brake fluid can affect hydraulic performance.

Common contaminants include:

Damaged Wiring

Inspect the pressure sensor wiring for:

Corroded Connectors

Poor electrical connections can distort sensor voltage readings.

Inspect for:

Faulty Electronic Brake Control Module

Although uncommon, an internal EBCM fault may incorrectly interpret brake pressure sensor signals.

This should only be considered after all hydraulic and electrical tests have been completed.

How Serious Is C0298?

High.

The vehicle typically retains conventional hydraulic braking.

However, the EBCM usually disables:

Without these systems, braking performance during emergency situations may be significantly reduced.

Can You Drive With C0298?

Yes—but use caution.

Normal braking generally remains available.

However:

Driving should be limited until repairs are completed.

How to Diagnose C0298

1. Scan the ABS Module

Use a professional scan tool capable of accessing manufacturer-specific ABS data.

Check for related codes involving:

2. Inspect Brake Fluid

Verify:

Replace contaminated brake fluid if necessary.

3. Bleed the Brake System

If air is suspected:

4. Monitor Live Brake Pressure Data

Observe brake pressure while gradually applying the brake pedal.

The pressure should:

Erratic or implausible readings indicate sensor or hydraulic faults.

5. Inspect Wiring and Connectors

Inspect the brake pressure sensor harness for:

Repair wiring before replacing expensive components.

6. Test Sensor Voltage

Using a digital multimeter:

Verify:

Compare readings with manufacturer specifications.

7. Inspect the Hydraulic Control Unit

If electrical testing passes, inspect the Hydraulic Control Unit for:

Many vehicles require HCU replacement when the integrated pressure sensor fails.

Common Repairs

RepairEstimated Cost
Replace brake pressure sensor$100–350
Repair damaged wiring$100–300
Replace damaged connector$75–200
Brake fluid flush$100–200
Bleed brake system$100–250
Replace Hydraulic Control Unit$700–1,800
Replace Electronic Brake Control Module$800–2,000
Module programming$150–300

Common Diagnostic Mistakes

Technicians frequently:

Vehicles Commonly Affected

C0298 is commonly reported on:

Similar brake pressure sensor performance faults also appear on many Ford, Toyota, Honda, Nissan, Hyundai, Kia, Volkswagen, BMW, Mercedes-Benz, Subaru, and Stellantis vehicles equipped with electronic brake pressure monitoring systems.

How to Prevent C0298

Reduce the likelihood of C0298 by:

Frequently Asked Questions

What causes C0298?

The most common causes include a faulty brake pressure sensor, Hydraulic Control Unit failure, low brake fluid, air in the brake lines, contaminated brake fluid, damaged wiring, or connector corrosion.

Is C0298 serious?

Yes.

Although standard braking usually remains available, the loss of ABS, traction control, and stability control reduces braking safety during emergency situations and poor road conditions.

Can low brake fluid cause C0298?

Yes.

Low brake fluid can reduce hydraulic pressure enough to trigger brake pressure sensor performance faults.

Does C0298 mean I need a new ABS module?

Not necessarily.

Many vehicles only require brake fluid service, wiring repairs, or pressure sensor replacement. The Hydraulic Control Unit or EBCM should only be replaced after proper testing.

Will C0298 affect normal braking?

Usually not.

The hydraulic braking system continues to operate normally, but advanced electronic braking functions will typically be disabled.

Final Thoughts

The C0298 code indicates the Electronic Brake Control Module has detected abnormal performance from the brake pressure sensor, preventing it from accurately measuring hydraulic brake pressure. Although conventional braking generally remains functional, advanced safety systems such as ABS, traction control, electronic stability control, brake assist, and electronic brakeforce distribution are typically disabled until the issue is corrected.

Most C0298 repairs involve verifying brake fluid condition, bleeding the hydraulic system, testing the brake pressure sensor, inspecting wiring and connectors, and evaluating the Hydraulic Control Unit before replacing expensive components. Following a systematic diagnostic process helps identify the root cause while avoiding unnecessary parts replacement.

For additional chassis diagnostics and repair guides, browse our complete Chassis (C) OBD-II Code Library:

Related Articles

Exit mobile version