Bosch Refrigerator Error Code Er r1

The Er r1 error code on a Bosch refrigerator indicates a fault condition in the refrigerator compartment temperature sensor circuit. Specifically, the control module has detected either an open circuit (interruption) or a short circuit in the sensor signal line. The refrigerator compartment sensor is a negative temperature coefficient (NTC) thermistor, meaning its electrical resistance changes predictably with temperature. When the control module reads a resistance value outside the expected range, whether due to a broken wire, corroded connector, or failed sensor, it flags this code to alert the user that temperature monitoring for the fresh food section is compromised.

Because the refrigerator compartment sensor provides real-time temperature data to the control module, a fault here prevents the system from accurately regulating cooling cycles. Without reliable sensor input, the compressor and evaporator fan may run erratically, run continuously, or fail to run at all, depending on how the control module handles the fault condition. Food spoilage is a realistic risk if the error is left unaddressed for an extended period.

The first diagnostic step specified for this code is testing the control module itself. This is important because a faulty control module can misread or generate false sensor fault signals even when the sensor and wiring are intact. Diagnosis should therefore include checking the sensor's resistance value, inspecting the wiring harness for damage or corrosion, and verifying connector integrity before concluding that the control module requires replacement.