Bosch Refrigerator Error Code E9070

The E9070 error code on a Bosch refrigerator indicates a fault with evaporator sensor 2, specifically that the sensor circuit has been detected as either open (broken circuit) or shorted (circuit path collapsed to near-zero resistance). Evaporator sensors monitor the temperature of the evaporator coil during the cooling and defrost cycles. Bosch refrigerators with dual evaporator systems use multiple sensors to independently track conditions in the fresh food and freezer compartments, and evaporator sensor 2 typically corresponds to one of these zones. When the control board reads a resistance value outside the expected range for a functioning NTC thermistor, it logs this fault and may restrict or alter cooling operation to protect the system.

An open circuit condition means the sensor or its wiring harness has a break, preventing any signal from reaching the control board. A short circuit condition means the sensor leads or wiring have contacted each other or a grounded surface, causing an abnormally low resistance reading. Both conditions produce unusable temperature data. NTC thermistors used in refrigerator evaporator sensors typically follow a predictable resistance curve relative to temperature, and a reading that falls outside the expected range at any given ambient condition will trigger this code.

Common sources of this fault include physical sensor failure due to age or moisture intrusion, damaged wiring harness connections near the evaporator, and connector corrosion from condensation exposure. Ice buildup around the sensor mounting point can also stress the wiring over time. Diagnosis involves unplugging the sensor connector and measuring resistance across the sensor terminals with a multimeter, then comparing the reading to the expected value for the current evaporator temperature.