Bosch Oven Error Code E104

E104 means the cavity 1 temperature sensor has shorted to ground, producing an invalid signal that the control board cannot use to regulate oven temperature. As a safety response, the oven disables all heating elements and runs the cooling fan at high speed. The code points to a problem in the sensor itself, the wiring harness between the sensor and control board, or in some cases the control module.

No, it is not safe or practical to use the oven while E104 is active because the control system has disabled all heating elements as a protective measure. Attempting to force operation while a sensor fault is present could result in uncontrolled temperatures or additional component damage. The oven should not be used until the fault is diagnosed and repaired.

Resetting the oven by cycling power may temporarily clear the code from the display, but E104 will return as soon as the control board detects the shorted sensor condition again. A reset does not address the underlying wiring fault or component failure. The code will continue appearing until the root cause, whether a damaged harness, failed sensor, or defective control module, is identified and corrected.

A knowledgeable DIYer can inspect the wiring harness for visible damage, check connector terminals, and test the sensor resistance with a multimeter. If the sensor has failed, replacing it is a straightforward repair on most Bosch oven models. However, if the wiring harness requires splicing or the control module is the suspected cause, professional repair is recommended to avoid further damage.

If only the temperature sensor needs replacement, parts typically range from $20 to $80 depending on the model, and the repair is relatively inexpensive if done without a service call. If the wiring harness requires repair or replacement, costs can rise to the $100 to $250 range for parts and labor. A control module replacement is the most expensive scenario, often ranging from $200 to $500 or more including professional installation.