OK, with some e-mail information back from Jim at Zero Gravity I have some clarification on a few things. The TCS needs two basic things to get it going, a TPS signal and an RPM signal. After that, everything the transmission needs is transmitted to it on the CAN bus. The shift tables and shift timing are still resident in the transmission so I will still need HP tuners to set those up directly in the trans. Some of the features I described above i can still make work, but I will have to experiment some because some of the setup will be in the transmission. Looks like I can still swap shift tables from the 2650 via digital inputs which will be translated to CAN and sent to the transmission.
I spent part of the last two days experimenting with RPM signals. I know i can get the TPS signal there because I already have that in my 4L60e standalone. I first tried attaching to the 58x crank angle sensor. This is the factory 3.5 crank sensor hooked up like original to the ECU which feeds my stock tach. The timing was funny as the TCU appeared to only read the 2x gap it the wheel and give one pulse per rev. Scaling was set to get the right reading but the signal would glitch badly over 1500 RPM. I played more today with the filter settings and got it to work up to 3200 RPM (my redline) Knowing the tach would still need to function I then ran a test with the crank signal piggybacked to both the TCU and ECU. That did not work well as it would glitch the factory tach so after about 10 more minutes of testing I decided to abandon that approach.
There are two other approaches I can take, add another mag or hall effect sensor somewhere on the crank or flywheel end of the rotating parts, or use a tach pickup on the alternator. Knowing my alternator had a pickup, I decided to test that but was foiled when I discovered the wire harness I bought for it 4 years ago did not have a fourth wire for the tach (P terminal) pickup. I found the proper pigtail at a local alternator shop for $8 cash and picked it up. After soldering that in I ran a quick test and it works perfectly. I have the scaling close and will hone it in once I have everything wired properly into the vehicle. The only drawback to this approach is the case of a broken belt, the RPM signal will drop out. In that case, I can't get far anyway without the water pump turning. I'll have to test the failsafe performance by unplugging the RPM sensor once I'm up and going.
