Bosch Refrigerator Error Code F52

The F52 error code on a Bosch refrigerator indicates a fault in the finger protection sensor system associated with the ice dispenser. Specifically, the reference measurement taken by the finger protection circuit has returned an abnormal value: the measured signal recorded when the LED is actuated is higher than the signal recorded when the LED is off. Under normal operation, the sensor should detect a clear contrast between the LED-on and LED-off states. When that relationship is inverted or the baseline reading is too low, the control system flags F52 to prevent the dispenser from operating in an unsafe or unreliable condition.

The finger protection system uses an infrared LED and a corresponding receiver to detect whether an obstruction, such as a hand or finger, is present in the ice dispenser chute. The electronics module evaluates the difference between the actuated and non-actuated LED measurements to establish a reliable reference point. A reading where the LED-on value exceeds the LED-off value suggests the sensor baseline is corrupted, possibly due to contamination in the dispenser slot, a poor electrical connection at plug X504 on the electronics module, or a fault within the finger protection electronics module itself.

Diagnosis should begin at plug X504 on the electronics module, verifying the connector is fully seated and free of corrosion or debris. The ice dispenser slot should then be inspected and cleaned, as ice buildup, residue, or foreign material near the sensor window can scatter infrared light and distort readings. If the connection and the slot condition check out, the finger protection electronics module should be tested or replaced, as an internal component failure can produce this inverted signal relationship.