Bosch Oven Error Code E204

E204 on a Bosch oven means the temperature sensor in the second oven cavity has been detected as shorted to ground. This fault causes the oven to stop all heating in cavity 2 and run the cooling fan at high speed as a safety precaution. The issue can originate from damaged wiring, a failed sensor, or in some cases a faulty control module.

No, it is not safe or practical to use the second oven cavity while the E204 code is active, because the oven has disabled heating in that section entirely. The cooling fan running at high speed is a protective response, not a sign of normal operation. Continued use should be avoided until the underlying fault is diagnosed and corrected.

Repair costs depend on which component is at fault. A replacement cavity temperature sensor typically costs between $20 and $80 for the part, and a professional repair including labor can range from $100 to $250. If the control module is the cause, parts alone can range from $150 to $400 or more, with total repair costs potentially reaching $300 to $600 depending on the technician's rates and the specific oven model.

A knowledgeable DIYer can diagnose the E204 error by visually inspecting the wiring harness for pinches or damage and testing the cavity 2 temperature sensor with a multimeter. If the wiring is intact and the sensor resistance tests correctly, the control module may need professional evaluation. Replacing the sensor is a manageable repair for someone comfortable working with appliance wiring, but control module replacement is typically better handled by a qualified technician.

A power reset may temporarily clear the E204 code from the display, but the fault will return if the underlying problem with the sensor or wiring has not been resolved. Because the control continuously monitors sensor resistance during operation, a shorted sensor or damaged wire will trigger the code again as soon as the oven restarts. A permanent fix requires identifying and correcting the root cause.