4wd nightmare

New parts:
Front diff actuator
Transfer case assembly

Swapped known good- 4wd ECU and 4wd switch.
2015 Tacoma when switched to 4 wheel drive the driveshaft from transfer case engages as does the front axles, however my 4wd light continuously flashes like it hasn't engaged. When going back to 2wd the light continuously flashes and will not disengage until truck is shut off and turned back on. Have tried turning truck off and back on with switch in 4H but the light still just flashes. The only component left I suspect is somewhere in the harness?

 

Or the indicator switches for the transfer case and ADD.

 

Transfer case came with new switches

 

Doesn't mean it works. Techstream would be beneficial to let you know what indicator isn't indicating the proper state.

 

What is it under on techstream?

 

The 4wd ECU should have the state of the dash switch and the state of all the indicators. Look for any indicators that don't match the state requested by the switch. Start there.

 

Take voltage readings at the 4wd ECU once it’s locked into 4wd and report back. There will be a simple answer to your woes.

 

Have you tried this
https://www.tacomaworld.com/threads/how-to-trouble-shoot-4x4-actuator.263525/page-7#post-8538436

 

This should help with doing this.

https://www.tacomaworld.com/threads/4x4-problem-i-cant-resolve.575092/#post-19056025