C0131

What the Code Means

C0131 points to a fault in the brake fluid pressure sensor circuit. The sensor is built directly into the ABS pump housing and continuously measures pressure in the brake system circuit.

The DSC system uses this data: without a reliable pressure signal, the control module can't correctly assess braking force or run its traction-control and stability logic. The fault is logged when the sensor signal goes out of range or disappears entirely — whether from a failed sensor, its circuit, or the ABS unit itself.

Symptoms

• The ABS and DSC warning lights come on in the instrument cluster.
• A scanner logs a brake pressure sensor fault.

Because the sensor is built into the ABS pump, you may not feel any obvious change at the brake pedal — the main sign is the warning lights and the stored code.

Diagnosis and Repair

1. Read fault codes with a diagnostic scanner (ISTA) and confirm C0131 is current.
2. Watch brake fluid pressure data in real time: no reading or unrealistic values point to a failed sensor or circuit.
3. Check the wiring and connectors at the ABS module for damage and corrosion.
4. Since the sensor is built into the ABS pump, a confirmed fault means replacing or rebuilding the ABS pump.
5. After replacement, bleed the brake system (on an ABS unit, bleeding follows the procedure with pump activation via the diagnostic tool).
6. Clear the codes and do a test drive to confirm the code doesn't return and the ABS/DSC lights stay off.

Related Problems

• DSC failure: without pressure data, the control module can't perform stability control correctly.
• Higher risk of a skid, especially on slippery surfaces and during emergency maneuvers.

Don't put off the repair: a failed pressure sensor leaves the car with no stability control at all, and the ABS unit fault can get worse over time.