Trail Blazers SS LS2 Harness?

sublime1996525

New Member
Apr 15, 2022
29
Salt Lake City, UT
For my LS swap I’m using the LS2 from a 2008 TBSS. I also have the engine harness and ECM from it. Has anyone used this harness setup with a T56? I can’t find much info but a few threads on someone having a hard time programming their ECM for a T56 swap.

I’m wondering if I should bite the bullet and go Terminator X or….?
 

Gamma454

New Member
Jan 1, 2022
14
For my LS swap I’m using the LS2 from a 2008 TBSS. I also have the engine harness and ECM from it. Has anyone used this harness setup with a T56? I can’t find much info but a few threads on someone having a hard time programming their ECM for a T56 swap.

I’m wondering if I should bite the bullet and go Terminator X or….?
I’m just getting the Holley. Has fuel pump, fan control as well
 

73Z L92

Veteran Member
Jan 25, 2011
472
Carlos, MN
I'm 99% sure you can use the ECM. Just needs to have the auto trans tune out and the T56 tuned in. Make sure you add a vss signal to the T56 tune. Makes tuning easier.
Wiring I don't know. You might be better off buying a after market harness than trying to cobble together the TBSS wiring harness.
You might ask the same question over LS1tech.com
 

ErikNORCAL

Veteran Member
Aug 6, 2003
1,202
now in VA
Is it an E38 computer? You will need someone with a GM programmer and a VIN from something like a 2008 Corvette to flash that ECM.. but a VIN you know had a manual trans… write entire from HPtuners isn’t enough to get the various manual trans cells active. your throttle body should also match the model you are programming the OS for.
If the T56 is a takeout, it should have a vss plug on it.
Also check the OBD2 port has pins in 6 and 14 (iirc), 2008 was the year CAN was standardized in GM models. Not too sure if it makes a huge difference but read some earlier models had it and others didn’t.
Might want to put this in high tech section.. and, personal opinion, kind of Leaning towards aftermarket on swap vehicles but have no personal experience on aftermarket systems to back that up.
 

sublime1996525

New Member
Apr 15, 2022
29
Salt Lake City, UT
Is it an E38 computer? You will need someone with a GM programmer and a VIN from something like a 2008 Corvette to flash that ECM.. but a VIN you know had a manual trans… write entire from HPtuners isn’t enough to get the various manual trans cells active. your throttle body should also match the model you are programming the OS for.
If the T56 is a takeout, it should have a vss plug on it.
Also check the OBD2 port has pins in 6 and 14 (iirc), 2008 was the year CAN was standardized in GM models. Not too sure if it makes a huge difference but read some earlier models had it and others didn’t.
Might want to put this in high tech section.. and, personal opinion, kind of Leaning towards aftermarket on swap vehicles but have no personal experience on aftermarket systems to back that up.
I appreciate the feedback. It’s an E67 ECM. This sounds like it might be a bit of a nightmare to adapt.
 

ErikNORCAL

Veteran Member
Aug 6, 2003
1,202
now in VA
Matched hardware:
Not familiar with which manual trans equipped cars had E67s.
if you go in knowing… we’ll it shouldn’t be hard..but Still going down this rabbit hole on my e38. Just went to a 2013 ecm and matching vette throttle body from 2008 vette/throttle body (of course there was a throttle body change in 2009). Not sure it will work, discovered there was some sort of change in brake signal/launch control but hoping since it’s a swap vehicle without those signals.. fortunately the accelerator pedal matches (oh yeah, that needs to match too).

Matched Operating System (OS)
What happens if running an automatic OS in a manual trans is the the computer thinks it’s going 156mph, your odometer will spin that fast to keep up and transition from throttle to off or part gets janky and unpleasant things like a dead pedal (drive by wire). This has to do with the auto OS looking for the auto trans TCM. The manual OS gets around the lack of TCM. That is all I know.

Another option is run the matching automatic..
 

sublime1996525

New Member
Apr 15, 2022
29
Salt Lake City, UT
Matched hardware:
Not familiar with which manual trans equipped cars had E67s.
if you go in knowing… we’ll it shouldn’t be hard..but Still going down this rabbit hole on my e38. Just went to a 2013 ecm and matching vette throttle body from 2008 vette/throttle body (of course there was a throttle body change in 2009). Not sure it will work, discovered there was some sort of change in brake signal/launch control but hoping since it’s a swap vehicle without those signals.. fortunately the accelerator pedal matches (oh yeah, that needs to match too).

Matched Operating System (OS)
What happens if running an automatic OS in a manual trans is the the computer thinks it’s going 156mph, your odometer will spin that fast to keep up and transition from throttle to off or part gets janky and unpleasant things like a dead pedal (drive by wire). This has to do with the auto OS looking for the auto trans TCM. The manual OS gets around the lack of TCM. That is all I know.

Another option is run the matching automatic..
I think I've decided to just go with the Holley Terminator.
 

ErikNORCAL

Veteran Member
Aug 6, 2003
1,202
now in VA
For a platform swap, and one that also swaps transmissions, pretty sure aftermarket is a good choice so you don’t have to deal with the innuendos of an OEM architecture. Looking forward to hearing your thoughts after completion.
 




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