Hey Guys,

This past year my buddy built an expensive project vehicle with an 08 vintage LS3 and a T42. Someone supplied the harness and modules.

The vehicle didn't start or run, no less shift.

If got it running now with some 2008 Silverado calibrations, but it won't shift and the speedo only bounces.

I believe the problem is that he installed a 4L60e that does not have an ISS sensor and the tcm is expecting it.

I have no definitive answers from anyone that has successfully used a NON-ISS trans with a T42. Turning off

codes or telling the TCM the ISS is not present has not helped thus far.

Anyone have experience with this or can shed some light?

Your thoughts are much appreciated.

Chuck CoW