6L80 Tap Up/Down shifting
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6L80 Tap Up/Down shifting I have just finished installing GM LY6 engine and 6L80 transmission in my CJ7. This setup is working great in my Jeep. The only thing missing is Tap UP/DOWN shifting so I can manually control the tranny for example while off roading.
I have hardwired parallel resistors (8.25k ohm, 4.2 k ohm and 1.5 k ohm see pic.) to the pin 7 and also made some adjustments to the TCM with my HP Tuners software. But it does not work for me! I use old fashion B&M shifter to the PRND...
Can anyone tell me what setup I need to get the proper Tap UP/DOWN function - both regarding the hardware (wiring) and also the necessary ECM/TCM changes?
Jonas
I have hardwired parallel resistors (8.25k ohm, 4.2 k ohm and 1.5 k ohm see pic.) to the pin 7 and also made some adjustments to the TCM with my HP Tuners software. But it does not work for me! I use old fashion B&M shifter to the PRND...
Can anyone tell me what setup I need to get the proper Tap UP/DOWN function - both regarding the hardware (wiring) and also the necessary ECM/TCM changes?
Jonas
You cant get tap up tap down to work without having the BCM in place. In stock form on truck platforms the TU/TD switches are wired to the BCM. The BCM then sees the switch state change with the trans in M mode and the BCM broadcasts the gear change request to the TCM via the high speed serial BUS.
The diagram you posted is for a vette and the BCM is involved in the same way there as well. It operates in the background in conjunction with the TCM. To even experiment the TCM and ECM must be flashed for the correct year vette your motor and trans are and that is if and only if the svc # of the TCM/PCM match the vette svc #'s exactly before you could even begin trying to toy with it.
The diagram you posted is for a vette and the BCM is involved in the same way there as well. It operates in the background in conjunction with the TCM. To even experiment the TCM and ECM must be flashed for the correct year vette your motor and trans are and that is if and only if the svc # of the TCM/PCM match the vette svc #'s exactly before you could even begin trying to toy with it.
Last edited by 01WS6/tamu; Jan 10, 2015 at 12:23 AM.
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"The diagram you posted is for a vette and the BCM is involved in the same way there as well. It operates in the background in conjunction with the TCM. To even experiment the TCM and ECM must be flashed for the correct year vette your motor and trans are and that is if and only if the svc # of the TCM/PCM match the vette svc #'s exactly before you could even begin trying to toy with it."
Interesting. On my car I am using the 2011 Corvette program for both the ECM and TCM which I had reflashed. The service number for the ECM is correct but the TCM/6L80 is out of a 2010 vehicle which I think was a truck. I was hoping down the road to activate the TU/TD feature. I even brought the purple wire into the cabin area of the car. Hmmmmmm
Interesting. On my car I am using the 2011 Corvette program for both the ECM and TCM which I had reflashed. The service number for the ECM is correct but the TCM/6L80 is out of a 2010 vehicle which I think was a truck. I was hoping down the road to activate the TU/TD feature. I even brought the purple wire into the cabin area of the car. Hmmmmmm
The PCM and TCM must be flashed for a vette and be the correct service numbers as a vette for whatever year model your engine and trans and wiring harness combination is. Then and only then could you begin to experiment to see if it's possible. I'm not going to say it's impossible cause it may not be. To experiment you would need to do the above and wire it like the diagram. I would recommend using the vette paddle shifter switch assemblies and OEM connecting harness to make sure everything is factory at least then you may have a dam good chance at getting it to work.
Now I know for sure with the pcm flashed as truck and the tcm flashed as truck you cannot get the TU/TD to function I've tried it and the bcm is the stall point on that one because it's involved. The only reason it could possibly not work wiring it up as vette is IF other systems have to signal the TCM,and PCM it's safe to initiate TU/TD operation once the trans is in manual mode.
Now I know for sure with the pcm flashed as truck and the tcm flashed as truck you cannot get the TU/TD to function I've tried it and the bcm is the stall point on that one because it's involved. The only reason it could possibly not work wiring it up as vette is IF other systems have to signal the TCM,and PCM it's safe to initiate TU/TD operation once the trans is in manual mode.
Last edited by 01WS6/tamu; Jan 10, 2015 at 08:15 PM.
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The engine comes from a truck (2008 Sierra HD2500) and the transmission comes from a SUV (2009 Escalade). The ECM is flashed with the VIN from the truck I think. In HP Tuners there are several selections regarding the Tap Up/Down.
I think you can manually shift the 6L80 in the Cadillac. I have read about people that have managed to solve this somehow, I think without the BCM. Speartech is selling Tap Up/down box but I think they need the ECM and TCM to reprogram. I dont like to remove the TCM now (open the tranny).
Can I somehow see if I have atruck program or Vette program?
I think you can manually shift the 6L80 in the Cadillac. I have read about people that have managed to solve this somehow, I think without the BCM. Speartech is selling Tap Up/down box but I think they need the ECM and TCM to reprogram. I dont like to remove the TCM now (open the tranny).
Can I somehow see if I have atruck program or Vette program?
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OS versions The engine comes from a truck (2008 Sierra HD2500) and the transmission comes from a SUV (2009 Escalade). The ECM is flashed with the VIN from the truck I think. In HP Tuners there are several selections regarding the Tap Up/Down.
I think you can manually shift the 6L80 in the Cadillac. I have read about people that have managed to solve this somehow, I think without the BCM. Speartech is selling Tap Up/down box but I think they need the ECM and TCM to reprogram. I dont like to remove the TCM now (open the tranny).
Can I somehow see if I have atruck program or Vette program?
I think you can manually shift the 6L80 in the Cadillac. I have read about people that have managed to solve this somehow, I think without the BCM. Speartech is selling Tap Up/down box but I think they need the ECM and TCM to reprogram. I dont like to remove the TCM now (open the tranny).
Can I somehow see if I have atruck program or Vette program?
The ECM (E38) OS# 12619078 and TCM OS# is 24249179.
What OS # is required for the Corvette setup?
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Okay, the motor is a 2008 6.0L out of a truck and the 6L80 is out of a 2009 Escalade/truck. I was thinking maybe you could download a 2009 Corvette 6L80 file into your 2009 transmission and that would get it done.
You have to be careful on what year files you download as they can lock up the ECM/TCM if they are not of the correct service number. That is why I was staying with the same year with the Corvette program. It appears that the 2008 E38 is communicating OK with the 2009 T43 in your situation. Again you can talk to John at Speartech for answers.
I am thinking of adding the TUTD feature to my car down the road and that is why I am interested in this thread. For me I am looking at the Speartech shifter.
You have to be careful on what year files you download as they can lock up the ECM/TCM if they are not of the correct service number. That is why I was staying with the same year with the Corvette program. It appears that the 2008 E38 is communicating OK with the 2009 T43 in your situation. Again you can talk to John at Speartech for answers.
I am thinking of adding the TUTD feature to my car down the road and that is why I am interested in this thread. For me I am looking at the Speartech shifter.
