New to the forum and to LSx. I am having trouble getting a 2005 dbw lq4 swap running. It is a complete pull-out (confirmed running by seller) and I had harness modification and PCM unlock done by a provider on ebay.

My problem is that I get no rpm signal out of the PCM. Crank and cam sensors show signal into PCM on a scope but no RPM registers on scan tool while cranking. I also notice that my throttle doesnt open when pedal is activated - throttle body also makes clicking noises. PCM grounds test under .3V on drop test.

Identifix lists no RPM from PCM problem as bad PCM - fix is to replace PCM. My harness guy said that a bad TAC could cause no rpm also.

Both PCM and TAC for 2005 are pretty expensive. How should I proceed to troubleshoot this issue? I'm stumped. What should I do next? Is it true that PCM requires TAC module to register rpm? That seems unlikely but I am new to this stuff.