OBD-II trouble code
C0131: ABS/TCS System Pressure Circuit Malfunction
The ABS module detected a fault in the brake pressure sensor circuit it uses for anti-lock and traction control. ABS and traction/stability control are disabled, but your normal (base) brakes still work.
Quick facts
- System
- Chassis
- Category
- ABS / Hydraulic
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $200 – $900
- DIY difficulty
- Advanced DIY
What does C0131 mean?
The anti-lock brake and traction control system (ABS/TCS) relies on a brake pressure sensor to know how much hydraulic pressure is in the system. The electronic brake control module (EBCM) uses that reading to decide how to modulate the wheels during anti-lock, traction, and stability events. C0131 sets when the module sees a problem with this pressure-sensor signal — it is out of range, implausible, electrically open or shorted, or does not match the module's expectation.
With an untrustworthy pressure signal, the module can no longer safely run its pressure-based control, so it disables ABS, traction control, and stability control and turns on the warning lights. Your standard hydraulic brakes still function — the vehicle stops normally when you press the pedal — but the electronic assistance is offline until the fault is corrected.
On many vehicles the pressure sensor is integral to the EBCM/hydraulic control unit or the master cylinder assembly, so a genuine sensor failure can mean replacing or rebuilding that unit; on others the sensor is a serviceable part with its own connector. As always, the sensor needs clean power, ground, and signal wiring — corroded connectors, damaged wiring, or low system voltage can produce C0131 without the sensor being bad. Some systems also require a sensor calibration or relearn after service, so confirm the procedure in service data for your specific vehicle. Because pressure faults sometimes accompany other internal EBCM codes, read all the codes together before deciding on a repair.
Common causes
- Failed brake pressure sensor (often integral to the EBCM or master cylinder)
- Corroded, loose, or damaged pressure-sensor connector
- Open or shorted wiring in the sensor signal circuit
- Low system voltage affecting the sensor reference
- Missing calibration/relearn after brake or module service
- EBCM internal fault (less common)
Symptoms
- ABS warning light on
- Traction control and stability control (ESC) warning lights on
- ABS, traction, and stability features disabled
- Normal (base) braking still works
- Occasionally a firmer or less consistent brake-assist feel on affected systems
Diagnostic steps
- 1.Scan the ABS module and record C0131 and any companion codes to see whether the fault is isolated or part of a wider EBCM problem.
- 2.Inspect the pressure-sensor connector and wiring for corrosion, damage, or a loose fit.
- 3.Compare the sensor's live-data pressure reading against expected values (near zero with the pedal released, rising as the pedal is pressed).
- 4.Check power, ground, and reference voltage at the sensor with the connector back-probed.
- 5.Confirm whether your vehicle uses a serviceable sensor or one integral to the EBCM/master cylinder, and whether a calibration/relearn is required.
- 6.Repair the wiring or replace the sensor (or unit) as indicated, perform any required relearn, clear the codes, and road-test.
Repair cost
$200 – $900
When the pressure sensor is a separate, serviceable part, the repair can be in the $150-$400 range including labor and any relearn. When the sensor is integral to the EBCM or master cylinder assembly, the fix trends higher — often $400-$900 — because the larger unit must be replaced and programmed. Wiring or connector repairs are cheaper; rule those out first.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with abs module / ebcm replacement preselected. Adjust labor rate and vehicle category to fit your situation.
Related repairs
DIY vs shop
This is an advanced DIY job. It typically requires specialty tools, scan-tool access, lifting equipment, or careful sequencing to avoid causing new failures. Plan for extended downtime and have a backup vehicle. Most owners are better served by a shop that has done this repair before.