Bosch Dishwasher Error Code Er:09

Er:09 means the main control board and the inverter board have lost communication with each other. The inverter board controls the wash pump motor, so when this link is broken, the dishwasher cannot operate safely and shuts down. The most common cause is a problem with the wire harness connecting these two boards.

A reset may temporarily clear the code, but if the underlying wiring or component issue is not resolved, the error will return once the dishwasher attempts to run a cycle. Resetting should only be used after a confirmed repair to verify the fault has been corrected, not as a substitute for diagnosis.

Repair costs vary depending on which component is at fault. Wire harness replacement parts typically range from $30 to $80, and with labor the total repair cost is commonly between $100 and $250. If the inverter board or control board requires replacement, parts alone can range from $80 to $300 or more, which will increase the overall repair cost significantly.

A knowledgeable DIYer can inspect the wire harness and connectors between the control board and inverter board for obvious damage, corrosion, or loose connections. If the harness is visibly damaged, replacing it is a straightforward repair. However, if the fault persists after harness inspection, diagnosing the inverter or control board typically requires more advanced electrical testing and is better handled by a technician.

No, the dishwasher will not complete a cycle while Er:09 is active because the control board cannot properly communicate with the inverter that drives the wash pump. Attempting to run the machine in this condition is not recommended. The dishwasher should remain out of service until the communication fault is diagnosed and repaired.