Fault Code Lookup

HVAC Sales Master
COMM LED (amber)
Flashes the number of communicating devices connected on bus
This code typically points to

    Next checks to confirm
    1. Count flashes to verify expected number of devices connected
    2. If count is wrong, check bus wiring and device power

    Escalation
    None by itself — diagnostic aid
    Reset behavior
    Updates dynamically with bus state.
    Informational
    No action needed
    Source
    Trane Hyperion *AM8/TAM8 Field Reference Data, Alert Codes, p.22