Originally Posted by AKlowriderZ71

It's not easier to add the relay and run without a segment swap. And doing it that way has sometimes caused issues, with the fact that the pcm thinks the gear ratios are one thing, but the 80E gear ratios are different. For that reason alone, I always do the segment swap. It's the best, and IMHO, also the simplest.

You will need to swap the wires in the round connector, as shown in your pic.

Your 60E does not have an input shaft speed sensor. Your 80E does, and the PCM needs that info. So you'll make that 2 wire harness, plug it into the front sensor on the left side of the 80E, and run those 2 wires to the PCM as shown in your pic. Be sure to "twist" that harness.

Send your 60E tune file, and also an 80E tune file WITH A MATCHING OS, to support@hptuners.com and they will do the segment swap for you. When you get it back, you must do a "write entire" flash to complete the process. After all of that, you'll likely want/need to adjust shift points and firmess, but that's all up to you.

Are you running on a custom or upgraded HPT OS?

Originally Posted by Atomic

Got my problem figured out, and since it deals directly with the relay method I'll throw it in here.

I read something on the hptuners forum about the speedo being off causing this type of error, so I double checked my vss pulses and corrected it and the speedo is dead-nuts on for what it should be with the tire height and gear ratios. However, there is still a ~150rpm slip when its "locked", but the math isnt showing that... Remembering I am still using the 60e tune, I checked the numbers with the 60es deeper OD and sure enough, that would make the "TCC Slip" equal to about 0. What this implies is the PCM has knowledge of the gear ratios in the transmissions and doesnt just use the speed sensors to calculate it.

Case in point;
I logged engine rpm, input shaft rpm, output shaft rpm, and tcc slip in a steady state highway situation. For this particular case these were the values:

Engine - 2212
Input - 2052
Output - 2953

So "TCC Slip" is defined as the difference between the engine rpm and input shaft rpm, so in this case it is measured as 2212-2052=160, which is exactly what HPT showed. But lets keep in mind where these numbers come from. The physical sensors are on the engine (crank sensor) and output shaft (vss sensor), so where does that input rpm number come from? Took me a while to figure out that it is a calculated value...based on the transmission ratios, and as far as the PCM knows im still using a 60e, not an 80e. So lets repeat the exercise for TCC Slip accounting for the correct ratios and knowledge that the physical sensors are accurate (engine and output).
[2212-(2953*.75)] = 0 That is to say the engine speed minus the trans output speed times the OD ratio I actually have gives me the true input rpm and now produces a TCC Slip value of 0 rpm. Excellent.

I am relieved to finally have an answer I am happy with, but disappointed there isnt a way to fix the problem without doing a segment swap as there is not access to the gears the PCM assumes you have. I dont want to do the segment swap because the torque converter unlocking at 0% throttle is extremely annoying. Secondly, if I am in a condition where the clutch is engaged, its at high speeds, so if I let off the gas I want the additional engine braking.

If you are particularly interested in seeing the TCC Slip value making a custom PID to get the *true* TCC slip is not hard, it would simply be:
[engine rpm] -[trans_output_shaft_rpm*actual_trans_ratio] = TCC Slip
However, if you wanted the slip in every gear, you would need to make 4 pids based on the 80e ratios for 1st through 4th (2.48, 1.48, 1, .75). The above case only works in 4th gear.
I was mainly concerned with this because I thought there was a legitimate hardware problem, which I didnt want cooking my clutches and ultimately destroying an expensive drivetrain.

Originally Posted by KySilverado

The 80E has 2 speed sensors in it. The 60E only one. You have to get it connected to the PCM. The connectors and pin outs is pretty well documents here. I won't go into that. I'll show you what I did for it.

Happened to have the old battery acid eaten wiring harness that came on my junkyard 6.0L when I did that swap. It happened to be an 80e harness.



I dug out the connector, wiring and PCM pins from the harness. I'll wrap these up in thier own protector and run them to the PCM. Main reason I did this is now I won't have to round up the PCM pins.

You'll connect the new sensor to PCM via PINS 22 (RED) and 23(Blue). Just as this 4l80e harness is wired.




I also removed the 4l80 style main connection from the old harness in case it fits in better than the 60E connector. I've seen you can buy these cheap on e-bay. I've not read that this is necessary but might install a little cleaner.


Circled the VSS sensor I'm talking about that has to be wired up. The other will be in its original location on the end of the transfer case.



I also want to note that connectors on these things are modular. I was able to dismantle the PCM connector to get the pins out easily and I also dismantled the VSS connector and swapped out the connector because a snap was broken on the old 6.0L VSS connector.