hi all. hope to add some useful and concise information this thread lacks. happy to have the light cleared finally now can re-assemble the car.
need to order a replacement obd with the TR232 chip and a fiat 3 to 16 pin obd adapter port.
VAG-COM KKL OBD2 USB Cable (FTDI FT232RL Chip) + Fiat 3 Pin Adapter Cable
then can complete the airbag reset procedure.
ecu part number 60625181
To connect to the 60625181 airbag ECU the L-line must NOT be connected, otherwise you will get the "ECU Response Timeout" error message.
the L line is the LTB-WHT to the 3-pin diag connector (pin 8 on airbag ecu)
the K line is the WHT-RED to the 3-pin diag connector (pin 9 on airbag ecu)
have 2.7 ohm resistors in the drivers' airbag and driver's pretensioner since those components were removed.
removed the L-line LTB-WHT to the 3-pin diag connector (pin 8 on airbag ecu)
from airbag harness side (insert small flat blade into pin socket end to pry connector and pull out from connector harness side)
ran program in cmd.exe 'trw2scan trw2.obd'
tried to clear twice, airbag light still on.
removed battery ground and wait two minutes, reconnect, restart car and observe for airbag light gone out.
tested airbag pretensioner resistance on drivers' seat 0.3 ohm (good)
tested with airbag and clockspring in place to confirm airbag light cleared
observe to keep resistors in place until all components are reinstalled.