C0131
- Chassis
- Generic (SAE)
Not urgent
Unlikely to affect driveability. Worth resolving so the light does not mask a future fault.
Master Cylinder Pressure Sensor Range/Performance
This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.
The ABS or stability control module has detected an implausible signal from the master cylinder brake pressure sensor. This sensor reports driver brake input and is used by ABS and ESP for control decisions.
A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.
- Safe to drive
- Unlikely to affect driveability. Worth resolving so the light does not mask a future fault.
- Urgency
- Not urgent
- Will it pass emissions
- Not affected
- Check engine light
- Varies
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Many vehicles show no symptom at all beyond the warning light. The absence of a symptom does not mean the fault is not real.
| # | Cause | How often | Component |
|---|---|---|---|
| 1 | Pressure sensor failed | Very common | — |
| 2 | Wiring or connector fault | Common | — |
| 3 | Air in brake system causing erratic pressure | Occasional | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- Master Cylinder Pressure Sensor
- ABS Control Module
- Esp Control Module
- Definition
- Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
- Diagnostic guidance
- Written and reviewed in-house. See our editorial policy.
- Review status
- Awaiting review
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