Bosch Washer Error Code Er:15

Er:15 on a Bosch washer indicates that the control board attempted to calibrate the pressure sensor and failed. The pressure sensor, also called a water level sensor or pressure transducer, monitors water fill levels inside the drum by detecting air pressure changes through a small plastic tube connected to the tub. During calibration, the control board sends a signal and expects a specific response from the sensor. When the returned signal falls outside acceptable parameters, the board registers Er:15 and halts operation to prevent overfilling or other water-level related faults.

The two primary failure points for this code are the pressure sensor itself and the wire harness connecting it to the control board. A faulty sensor may produce no signal, an erratic signal, or a signal that remains fixed regardless of actual water level. Wire harness issues include broken conductors, corroded terminals, pinched wires, or loose connector seats at either the sensor end or the board end. Either condition prevents the control board from completing its calibration routine.

Diagnosing Er:15 begins with running test P8, which is the designated pressure sensor diagnostic routine built into the Bosch service test program. This test isolates the sensor circuit and provides a direct indication of whether the sensor or harness is at fault. Visual inspection of the wiring harness for damage, corrosion, or disconnection should accompany the P8 test. If the harness checks out, the pressure sensor itself is the next component to evaluate and likely replace.