Brake Pressure Sensor B
Indicates a fault with the secondary brake pressure sensor.
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What it means (plain English)
The secondary brake pressure sensor measures hydraulic pressure in the brake system. If it fails or gives bad readings, the vehicle's brake system might think the brakes are not functioning properly, affecting stopping power.
What the computer is actually seeing
The engine control unit (ECU) monitors the voltage output from the secondary brake pressure sensor, which should typically be between 0.5V and 4.5V. If it reads outside this range or is steady at a certain value when it should be fluctuating, it triggers a fault code.
What a healthy reading looks like
Normal voltage should vary between 0.5V to 4.5V based on brake pedal position and system pressure.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Check the wiring and connectors to the brake pressure sensor for any visible damage or corrosion. Fix as needed and retest.
- 2Measure the voltage output at the brake pressure sensor connector with the key on and engine off. It should vary between 0.5V and 4.5V when the brake pedal is pressed.
- 3If the voltage is steady or out of range, replace the brake pressure sensor and retest.
- 4If the sensor is good and wiring is intact, check for issues in the hydraulic brake system that could affect pressure readings.
Common causes
- Faulty brake pressure sensor
- Wiring issues (fray or break)
- Connector problems (corrosion or loose connections)
- Hydraulic system issues affecting pressure
- ECU malfunction
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Moderate severity means you can drive, but you should fix it soon as it affects braking performance.
Will this code come back after I clear it?
If the issue is fixed, it shouldn’t return. If it does, there's an underlying problem still present.
Why does it pair with other SPNs?
Multiple SPNs may indicate related issues in the brake system, especially with pressure sensing and hydraulic integrity.
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