Toyota Avalon 2018–2019 — technical service bulletin
Bulletin T-TT-0516-18 · NHTSA communication 10153236 · issued Dec 18, 2018
Technical service bulletin
communication type
Equipment
component
2018–2019
model years
3
vehicle entries
Official summary
TT: The microphone circuit passes through the DCM before reaching the radio/navigation system. To simplify the diagnosis of the microphone, Safety Connect SOS button lights, and DCM (Telematics transceiver) inoperative conditions, refer to the procedure below to prevent unnecessary parts replacement.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.