So I have a 2011 RCSB here swapped by a local shop.

Original truck 2011 4.8L 4L60E variant.

Donor 2013 A6 harnesses and modules inside and out with 6L80E installed.

FAULT: No tachometer operation on the instrument cluster and also no tachometer operation in the HP Tuners scanner v2.24, v4.0 and current version. Also I get a -0- RPM display in the TECH2. All this while the engine is running.

To start with I flashed it with a 2013 A6 truck with TIS. I flashed ECM, TCM, BCM, IPC all with the same VIN as module replacement. All instrument panel operations are correct with the exception of the tachometer. The original IPC has also been installed and confirm no tachometer operation on it either and also all other gauges work.

Second, I have flashed the truck (all the same 4 modules) with two different 2011 VINs and experienced the same. No tachometer operation IPC or scanner.

Third, I now currently have it flashed with a 2010 RCSB all 4 modules and still no tachometer operation.

I have also tried a different 2010-2013 service number E38 with the exact same results.

I really don't know how to approach this especially with the TECH2 not displaying RPM.