What it means
The control module monitors brake pressure sensor A for a steady, plausible signal. It sets this code when the signal is intermittent or erratic.
At a glance
- Usually lights the ABS or stability-control warning light
- The engine or gearbox may go into limp mode
How it works
Brake pressure sensor A supplies pressure information that the control module uses for brake and stability functions. This code sets when sensor A's signal becomes intermittent or erratic instead of remaining plausible, often as a connection or harness fault appears under vibration.
Common causes
Most likely first.
- Connector loose or chafed wiring
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
Symptoms
- Brake or ABS warning light
- Brake pressure or stability-control functions may be limited
How to diagnose it
- Read freeze-frame and live data for brake pressure sensor A, comparing its signal with brake-pedal application and any other available pressure readings.
- Inspect sensor A's connector and harness for looseness, chafing, poor terminal fit, or routing against a vibrating part.
- With live data displayed, gently move the accessible harness sections to see whether sensor A's reading drops out, following safe vehicle procedures.
- Check sensor A's signal, supply, and ground circuits for intermittent opens or poor connections using the wiring diagram.
- If the wiring remains stable, test sensor A against the manufacturer's procedure and compare its response with the specified pressure behavior.
Common fixes
- Secure a loose sensor A connector and correct harness routing that allows vibration or chafing.
- Repair damaged or intermittently connected sensor A wiring.
- Replace corroded or loose terminals in the sensor A connector.
- Replace brake pressure sensor A only if its signal remains erratic with verified wiring and supply.
Can I keep driving?
Brake-pressure or stability functions may be limited while sensor A's signal is unreliable. Drive cautiously with extra stopping distance, avoid slippery roads, and stop if braking response changes.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.