LS1XJ

Alright, thought I was doing good. Got an 07 LQ4. came with harness and computer, but no TAC and no pedal assembly. Came out of a 2007 Sierra 2500, classic body style. I had originally read that no tac was needed and that it was part of the PCM, but apparently not so. What options do I have, anybody sell these inexpensive or should I just go cable?
D

futureuser

iTrader: (1)

Make sure you have an lq4 and not an ly6. If you need a tac module, shouldn't be a big deal to find one.

FastKat

iTrader: (10)

Agreed. You can find a pedal, TAC module, and probably the wiring harness too at a salvage yard. If you wanted to wait a couple weeks, I think I have all that stuff available.

LS1XJ

It doesn't have the front cam sensor and the vin shows it as lq4. My main problem is there aren't any local salvage yards that are worth anything. The few that I have called don't want to mess with pulling the tac module (half of them don't even know what it is) and they won't let me do it. Let me know fastkat, I am still a little ways out on needing them, but I wanted to to have them before I get to deep in it.

LS1XJ

Also, side question. I have also seen mixed info on the tcm on an 07, is it part of the pcm or a separate module. I'm starting to think I got screwed on this deal if so.

FastKat

iTrader: (10)

On an 07 truck, the PCM should control both the engine and the transmission. I do not think there is a separate TCM on the 07 trucks.

Bo185

On the 07 GMT800 "classic trucks" it will be an Gen III LQ4 and have a PCM, TAC, and pedal assy.

The GMT900 trucks 2007 up are Gen IV and have no separate TAC.

futureuser

iTrader: (1)

If you can't find a yard my guess is that the part costs less new than you think. Try gmpartsdirect.com
Since you have the vin, you can get the part number and price from your local dealer. Also, they might give you wholesale if you ask.

LS1XJ

It came out of a classic Sierra. I checked some prices on the tac module and they weren't too bad and I found some pedals here and there used. Then I just need the harness which I know lots of places sell. The TCM stuff is still a little confusing. The other swaps I have done have been older LS1 stuff and it was nice and simple, DBC, no tcm, and only real difference was early and late.The truck came with a 4l80e, I got a smoking deal on a 4l70e. Not exactly what I wanted, but right price right time. So, going on the consensus that there is no separate TCM, hopefully I can handle that issue with HPtuners. Again, more conflicting info on the wiring differences. From what I can tell you can do a 60e or 70e on something that originally had an 80e with minimal changes to wiring, mainly done with tuning. Again, a little out of my skill level. I am few thrown wrenches away from ordering a harness and computer to simplify everything.
I appreciate the feedback. And by the way it is going in an 89 Grand wagoneer. I have an LS1 in my cherokee and got addicted.

Bo185

The 4l70 will work just repin the harness and add the 60 tune into the PCM. Pretty sure you won't need the ISS (fwd VSS) on the 4l70 with the Gen III PCM. The 4l80 has a Fwd VSS as well.

do this just in reverse

http://www.performancetrucks.net/for...d.php?t=413157

LS1XJ

Things are finally coming together. I found the TAC, harness, and Pedal for about 200.00, brand spankin new. Got the tranny too, but I am a little concerened about switching from the 4l80 to 4l60/4l70 in hptuners. My experience so far has been minor editing, small cam, minor mods. Does anybody have a baseline I can start with, or what is the best way to do this?
Thanks,
DUstin

Bo185

Why not check out the hPtuners forum?

IDRIVEAG8GT

There's a .bin file laying somewhere around here on this site....

mramay

iTrader: (4)

If you still have the pedal, harness and TAC, I'd like to buy them. I have an LS6 bolted into a Mercedes 560SEC and need a TAC, but if your pedal matches it, that would be fine.