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lq9 with t56 harness?

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Old 11-24-2013, 06:06 PM
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Default lq9 with t56 harness?

I am getting a 2005 lq9 feom an escalade and will be mounting it to a 2002 Viper t56 tranny. My question is can I still use the harness and computer from the Escalade as it had an auto trans. If I can use it, what would need to be done to it to make it work? Thanks in advance.
Old 11-24-2013, 10:46 PM
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Reflash the computer and remove all the auto trans wires but the VSS. I'm fairly positive the auto and manuals use the same pins for VSS. Check lt1swap for pinouts.
Old 11-24-2013, 11:04 PM
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Originally Posted by skongolf
I am getting a 2005 lq9 feom an escalade and will be mounting it to a 2002 Viper t56 tranny.


Hey Steve, did you finally decide on a combination...???
Old 11-25-2013, 11:32 AM
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Originally Posted by CattleAc
Hey Steve, did you finally decide on a combination...???
Yep. I am going to go with an LQ9. Found one out of an 05 escalade with eveything for $1200, just waiting for the guy to get back in touch with me. As far as trans goes, I am looking at a T56 out of a Viper that has been modified for an LS application. Kind of $$ but I think its worth it.
Old 11-25-2013, 11:57 PM
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VSS is still the same for the T56..just wire the Harness for the T56 and program it.
Old 11-26-2013, 11:13 AM
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Sound like your getting your ducks in a row and getting ready to do the swap.. !...

The Viper / Mopar VSS used a Hall effect signal vs the GM which uses a Sine wave signal.. they are not compatiable.. They are also different in size with the GM Being larger. The Teeth count of the Reluctor wheel is less teeth. I have never been able to connect it to the PCM.. I use GPS Speedo to get my speed. You could also use a Electric Speedo that accepts the Hall signal.

BC

BTW.. I am no Electrical Expert.. so.. other that what I have read and found.. I just work around the problem.

Last edited by bczee; 11-26-2013 at 11:44 AM.
Old 11-26-2013, 11:36 AM
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The reverse lock-out function is important, and that's the only downfall to using a truck PCM with a T56. I bought a standalone module that taps into into the VSS wire to disengage the reverse lockout solenoid under 5mph.

http://www.samocoind.com/T56MODULE.html
Old 11-26-2013, 11:48 AM
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That is a nice feature.. but a bit costly..

Being on a Budget builds.. I just used a Hurst Line Lock button.
Old 11-26-2013, 11:48 AM
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We've wired the reverse lockout to the brake light switch. Works good you just have to be careful when braking at hwy speeds in 5/6 to avoid hitting reverse. Ive also put it on a button switch in earlier days. I dont believe you can wire the reverse switch up to an auto PCM file but you sure can change your OS and flash in a manul trans version. Theres write ups on how to do this in the tuning section. Ive also run them with no VSS feed into the PCM and then afterwards wired them in. I couldnt tell a difference in how the car ran/drove with or without.
Old 11-26-2013, 11:54 AM
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tsnow678 was going to tap into the brake light signal, I believe. I used a combination brake/torque converter control (lockup) switch when I installed my 4L80e - I'm going to try to use this as a means of controlling the reverse lockout feature.

Edit: I've also seen some install a softer spring/cut a coil in the OE spring for the reverse lockout, and bypass the solenoid completely.

Also, BC didn't mention it, but he has said that he hasn't seen any ill effects from not running VSS to the PCM.

Last edited by hookemdevils22; 11-26-2013 at 12:15 PM.
Old 11-26-2013, 03:01 PM
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skongolf,
I have an 05 LQ9 out of an escalade with a T56 out of an Fbody. I just want to add that you should make sure to get the pedal and TAC from the pullout. Mine came with adjustable pedals which I modified(seen in my not-yet-finished build thread).

Also, I was having drivability problems(throttle crash, trying to stall when clutched-in) and I found that my VSS was unplugged. your tune depnds on VSS for idle airflow adjustment, so if bczee is right about the diff signal, you should probly try to adapt it to make it work.

btw Jesse Bubb at Wait4Me performance did my harness and base tune-great to work with. I would suggest emailing Hanna Bubb since her response time is way better.
Good luck with the swap!



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