C0131 on 2013-2020 Chevrolet Trax: Brake Pressure Sensor Fault Causes and Fixes

What's Unique About the 2013-2020 Chevrolet TRAX

On the Chevrolet Trax and its platform-mates like the Buick Encore and Chevrolet Sonic, code C0131 is a well-documented pattern failure. The brake pressure sensor, which is integrated into the Brake Pressure Modulator Valve (BPMV), is the common point of failure. Furthermore, GM has issued multiple Technical Service Bulletins (the latest being PIC5704H) warning technicians that failing to remove a small shipping cap from the new BPMV during installation will immediately trigger this code and can damage the new, expensive part.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Generation note: The 2013-2020 year range covers the first generation of the Chevrolet Trax. This generation received a significant cosmetic and feature facelift for the 2017 model year, but the underlying GM Gamma II platform and the components related to code C0131 remained the same. The issue is common to both pre-facelift (2013-2016) and post-facelift (2017-2020) models, and extends to the second-generation Trax (up to 2022) per GM's TSBs.

Symptoms You May Notice

• ABS warning light is illuminated
• StabiliTrak or Traction Control System (TCS) warning light is illuminated
• "Service StabiliTrak" or "Service Traction Control" message on the driver information center
• In some related cases on the same platform, drivers report the engine power is reduced.

Most Likely Causes

1. Faulty Internal Brake Pressure Sensor 🔴 High Probability The sensor is integrated into the Brake Pressure Modulator Valve (BPMV) and is a known failure point on this GM Gamma II platform, affecting the Trax, Sonic, and Encore.
   How to confirm: A professional scan tool will show the brake pressure sensor reading as stuck, often at 5 volts, regardless of whether the brake pedal is pressed or released. Other fault conditions include the signal being less than 0.12V or greater than 3.2V for more than one second.
   Typical fix: Replace the entire Brake Pressure Modulator Valve (BPMV) assembly. The sensor is not available as a separate part.
   Est. part cost: $250-$450
2. Improper Installation of New BPMV 🟡 Medium Probability This is a well-documented issue specific to this repair, addressed directly in TSB PIC5704H. New BPMV units are shipped with a protective cap over the sensor port that must be removed.
   How to confirm: The code C0131 appears immediately after a new BPMV has been installed. The brake pressure sensor reading will be stuck at 5 volts. The technician must remove the module to visually inspect for the forgotten cap.
   Typical fix: The BPMV must be removed, the forgotten shipping cap must be taken off, and the unit reinstalled. In some cases, this error can damage both the new BPMV and the EBCM, requiring another replacement.
   Est. part cost: $0 if caught in time, otherwise the cost of a new BPMV.
3. Wiring or Connector Issue ⚪ Low Probability The engine harness can chafe against the G100 ground stud, potentially causing a variety of electrical issues and DTCs, including U0121 (Lost Communication with EBCM).
   How to confirm: Visually inspect the wiring harness and connector at the EBCM/BPMV for any signs of corrosion, damage, or loose pins. Perform a continuity and resistance test on the relevant circuits. If DTC C0870 is also present, diagnose that 5-volt reference circuit issue first. Inspect the engine harness near the G100 ground stud for chafing.
   Typical fix: Repair the damaged section of the wiring harness or clean/replace the connector.
   Est. part cost: $5-$50

Diagnosis Steps

1. Connect a professional-grade OBD-II scanner capable of reading chassis codes and live data from the EBCM (K17 Electric Brake Control Module).
2. Confirm that C0131 is the active or stored code. Note any other codes, especially C0870 (5-Volt Reference) or symptom codes like C0131 5A.
3. View the live data stream for the "Brake Pressure Sensor" parameter.
4. Observe the voltage reading with the brake pedal released and then fully depressed. If the voltage is stuck (often at 5V) and does not change, it confirms a sensor circuit fault. The fault can also trigger if the signal is <0.12V or >3.2V.
5. Inspect the EBCM connector and nearby wiring for any visible damage, corrosion, or chafing. Pay special attention to the engine harness near the G100 ground stud, a known chafe point.
6. If the BPMV has recently been replaced, confirm with the installer that the shipping plug was removed per TSB PIC5704H.
7. If the original BPMV is still installed and the wiring is intact, the BPMV assembly is faulty and requires replacement.
8. After replacement, perform the automated ABS bleed procedure 🎬 Watch: How to perform an automated ABS brake bleed. and the Brake Pressure Sensor Calibration using a compatible scan tool.

Parts You'll Likely Need

• Brake Pressure Modulator Valve (ABS Module) (OEM #42700533) — This assembly contains the non-serviceable brake pressure sensor that fails and causes code C0131. It is the primary and most common fix for this issue.
  Trusted brands: ACDelco
  OEM price range: $300-$500
  Aftermarket price range: $250-$400

Related Codes That Often Appear With This One

• C0131 5A —
• U0121 —

Technical Service Bulletins (TSBs) & Recalls

• PIC5704H: Diagnostic Tip - Traction and Stability Control Indicator on with Code C0131 Set After BPMV Replacement. This bulletin warns technicians about an installation error where a shipping cap is left on the new module, causing the code. It applies to Trax models up to 2022.
• PIC5704G, F, C, A: Earlier versions of the same TSB, showing the issue has been known since at least 2012-2013 and progressively updated to include more model years.
• 18-NA-114: This bulletin addresses a condition where the engine harness may chafe against the G100 ground stud, causing various DTCs, including lost communication with the EBCM (U0121).

Platform-Specific Known Issues

• As documented in GM TSB PIC5704H, leaving the shipping cap on a replacement Brake Pressure Modulator Valve during installation is a frequent error that will cause code C0131 to set immediately and can damage the new component.
• The diagnostic cost for an ABS light on a Trax is estimated to be between $122 and $179.
• The total replacement cost, including parts and labor, averages between $553 and $666 according to RepairPal.

Mechanic-Grade Diagnostic Values

• Brake Pressure Sensor Signal Voltage — expected: 0V with pedal released, >1.0V with pedal applied.. Failure: Voltage is < 0.12V or > 3.2V for more than 1 second, or stuck at a constant value (often 5V).
• Brake Pressure Sensor Supply Voltage — expected: 4.8 - 5.2 volts.. Failure: Voltage is < 4.5V or > 5.3V for more than 1 second.

Hidden / Shadow Codes Worth Checking

• C0131 00: Traction Control System Pressure Circuit Malfunction. This is the base code. (see via GM GDS2 or equivalent professional scan tool.)
• C0131 5A: Traction Control System Pressure Circuit Not Plausible. This indicates the sensor's signal is erratic or doesn't logically match other vehicle inputs like acceleration or deceleration. (see via GM GDS2 or equivalent professional scan tool.)

Scan Tool Commands That Help

• GDS2 / Tech2 / equivalent pro-level scanner: Automated Bleed Procedure — Required after replacing the BPMV to purge all air from the new hydraulic unit. The scan tool sequentially activates the ABS pump and solenoids while the technician bleeds each caliper.
• GDS2 / Tech2 / equivalent pro-level scanner: Brake Pressure Sensor Calibration — Required after replacing the EBCM or BPMV. This procedure learns the new sensor's baseline (zero pressure) value. The path is typically: Chassis > EBCM > Programming/Configuration > Brake Pressure Sensor Calibration.
• GDS2 / Tech2 / equivalent pro-level scanner: Brake Pedal Position Sensor Learn — While not directly for C0131, if the Brake Pedal Position (BPP) sensor is replaced during diagnosis, it must be calibrated. This is done in both the BCM and ECM menus.

Wiring & Ground Locations

• K17 — The Electronic Brake Control Module (EBCM) itself, which is bolted to the BPMV in the engine compartment.. This is the module that sets the code and receives the faulty signal from the internal sensor. The main 38-pin connector is the primary point for electrical testing.
• G100 — Engine compartment, on the left side of the engine.. A known issue documented in TSB 18-NA-114 is the engine wiring harness chafing against this ground stud. This can cause a variety of DTCs, including U0121 (Lost Communication with EBCM), which could be a root cause if C0131 is accompanied by communication codes.

Real Owner Repair Stories

• CorvetteForum user (Chevrolet Corvette C6) — C0131 code, Service ABS and Active Handling lights, no brake lights.
  ❌ Tried (didn't work) Clearing the code (it returned in 5 minutes), Checking for unplugged connectors
  ✅ What actually fixed it The issue was a faulty brake pedal position sensor (brake light switch). After replacing the sensor, a Tech 2 scan tool was required to perform the 'relearn' or 'calibration' procedure, which resolved all symptoms. This highlights that while C0131 on the Trax points to the BPMV, on other GM vehicles it can be the pedal sensor, and calibration is always key.

OEM Part Supersession History

• 95230592 → 94552161 — Part update/revision.
  Heads up: This supersession is noted for the platform-mate Chevrolet Sonic, indicating GM has updated the BPMV assembly over time. Always verify the correct part number for your specific vehicle's VIN.