LG EAD62707901 Serial Cable

LG TV Programming Cable 6FT DB9-Female to 3.5mm TRRS Connector Male
Serial Transfer Communication Devices to Program LG TVs

TRRS 3.5 mm Jack.
DB9-F Serial Port.

DB9_Female_Connector
TRRS_Connector

Wiring Schematic

DB9-F      TRRS Connector 3.5mm           Signal 
Pin 1   
Pin 2         Ring Pin-3                               Transmit Data
Pin 3         Tip Pin-1                                  Receive Data 
Pin 4         Ring Pin-2
Pin 5         Sleeve Pin-4                             Ground 
Pin 6
Pin 7
Pin 8
Pin 9
Shell                                                          Foil Shield        

Layout of TRRS.
SLEEVE(GROUND),RING,RING,TIP