ABS/TCS Pressure Sensor Circuit Malfunction
What does C0131 mean?
The C0131 code means the vehicle's onboard diagnostic system has detected: ABS/TCS Pressure Sensor Circuit Malfunction. This is a critical severity code.
Common Symptoms
- ABS warning light on
- Traction control light on
- Service StabiliTrak message on GM vehicles
- Harsh or no ABS activation
- Brake pedal feels different than normal
Probable Causes (Ranked by Likelihood)
- Failed pressure sensor inside ABS modulator Very High
- Electrical connection issue at ABS module High
- Contaminated brake fluid causing sensor fouling Moderate
- ABS hydraulic modulator internal failure Moderate
- ABS control module calibration error Low
Step-by-Step Diagnostic Procedure
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Scan for codes and check if pressure sensor data is available in live data
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Inspect ABS module electrical connectors for corrosion or damage
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Check brake fluid condition -- dark or contaminated fluid can affect internal sensors
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Perform ABS automated bleed procedure if available on your scan tool
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Test pressure sensor readings against specifications during brake apply
Frequently Asked Questions
Can the pressure sensor be replaced separately?
On most vehicles, the pressure sensor is integrated into the ABS hydraulic modulator assembly and cannot be replaced individually. The entire modulator unit typically needs replacement.
What is the Service StabiliTrak message?
This is a GM-specific message that appears when the ABS/stability control system detects a fault. C0131 is a common cause. It disables both traction control and stability control until the fault is repaired.
Will a brake fluid flush help with C0131?
If the code is caused by contaminated fluid fouling the sensor, a complete fluid flush may help. However, if the sensor has physically failed, fluid replacement alone will not fix the issue.