Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P15B3: Brake Fluid Pressure Sensor A Range/Performance Problem (2005-2006 M/T models)
- Turn the ignition switch ON (II).
- Check BRAKE FLUID PRESSURE SENSOR A with the HDS without pressing the brake pedal.
Is there 2.45 MPa or more?
- YES - Go to step 3.
- NO - The system is OK at this time. Check for poor connections or loose terminals at brake fluid pressure sensor A and the ECM.
- Turn the ignition switch OFF.
- Disconnect the brake fluid pressure sensor A 3P connector.
- Turn the ignition switch ON (II).
- Measure voltage between brake fluid pressure sensor A 3P connector terminals No. 1 and No. 2.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there about 5.0 V?
- YES - Replace brake fluid pressure sensor A (see BRAKE FLUID PRESSURE SENSOR REPLACEMENT ).
- NO - Go to step 7.
- Turn the ignition switch OFF, and wait for 10 seconds.
- Disconnect ECM connector C (31P).
- Connect ECM connector terminal C18 to body ground with a jumper wire.
- Check for continuity between brake fluid pressure sensor A 3P connector terminal No. 1 and body ground.Fig 3: Checking Continuity Between Brake Fluid Pressure Sensor 3P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
- YES - Update the ECM if it does not have the latest software, or substitute a known-good ECM (see ECM UPDATING AND SUBSTITUTION FOR TESTING-2002-2006 M/T MODELS AND CVT MODEL ), then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM (see ECM REPLACEMENT ).
- NO - Repair open in the wire between brake fluid pressure sensor A and the ECM (C18).
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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