Error code reference

Trane Furnace Error Code 10 Flash

Communication fault

Communication fault - blower motor no COMM response (BLW COMM ERR), inducer motor no COMM response (IND COMM ERR), system COMM error (SYS COMM ERR), blower COMM CRC error, inducer COMM CRC error, 24V COMM mismatch, or control failure.

First step from the service manual

Scroll User Interface to view Last 4 Faults; for SYS COMM ERR check if CONT900 is installed and verify ~12vDC from terminals D-B at IFC; for BLW COMM ERR check serial motor wires and 120 VAC at motor connector.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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