LT1 stand alone harness - first timer
Thread Starter
Teching In
Joined: Jan 2017
Posts: 22
Likes: 0
LT1 stand alone harness - first timer So i pulled the engine from my Caprice and also the wiring harness. Now i want to convert it to a standalone harness but as it's my first time this i not so straightforward.
As the LT1 is by far not popular but where i'm from (Belgium) it's what i get to work with. Finding information about this engine and the pin outs is not so easy.
My best scource so far is lt1swap.com, specifcally this page with wiring schematics:
http://lt1swap.com/95impalalt1.htm
But my harness is different from those schematics although quite similar.
The biggest question i have is how do i know what i can remove from the harness and what not?
And is it likely that faults will start to pop up in the ecu when certain connectors are not connected, how do i get round that?
As the LT1 is by far not popular but where i'm from (Belgium) it's what i get to work with. Finding information about this engine and the pin outs is not so easy.
My best scource so far is lt1swap.com, specifcally this page with wiring schematics:
http://lt1swap.com/95impalalt1.htm
But my harness is different from those schematics although quite similar.
The biggest question i have is how do i know what i can remove from the harness and what not?
And is it likely that faults will start to pop up in the ecu when certain connectors are not connected, how do i get round that?
TECH Fanatic
Joined: Dec 2017
Posts: 1,476
Likes: 270
From: Bossier City, Louisiana
Hello Dieter,
Small world, I used to live in Mons-Casteau back in 1994-97. Yes, faults will show up for the things you are deleting from your harness. But we deal with those by modifying the program running inside the PCM - we use an application called "HP Tuners" though there are other apps that can also do this. Basically, HP Tuners tells the Powertrain Control Module to either ignore those faults or to not illuminate the Check Engine Light / Malfunction Indicator Light. In the best case, these faults will not even show up when a DTC code reader is connected to the On Board Diagnostics (OBD) II connector.
Here below is what my local tuner person who has HP Tuners did to my PCM:
Startup and at temp idle raised 100 rpm
PE Delay set to zero
Cat Overtemp Disabled
All EVAP, EGR, Fuel Sender, and Rear O2 codes deleted
Speedo and shift points corrected for current tire/gear
Max line psi disabled in case of MAF failure
VATS turned off no relearn necessary - Vehicle Anti Theft System
Fans Activated
For this, the charge was $175 USD. His effort only cost $75 but he had to buy two "credits" for $50 each from the HP Tuner company to "license" the new operating system inside my PCM.
So I think your difficulty will be to find somebody in Belgium that has HP Tuners or a similar program to modify your PCM.
Rick
Small world, I used to live in Mons-Casteau back in 1994-97. Yes, faults will show up for the things you are deleting from your harness. But we deal with those by modifying the program running inside the PCM - we use an application called "HP Tuners" though there are other apps that can also do this. Basically, HP Tuners tells the Powertrain Control Module to either ignore those faults or to not illuminate the Check Engine Light / Malfunction Indicator Light. In the best case, these faults will not even show up when a DTC code reader is connected to the On Board Diagnostics (OBD) II connector.
Here below is what my local tuner person who has HP Tuners did to my PCM:
Startup and at temp idle raised 100 rpm
PE Delay set to zero
Cat Overtemp Disabled
All EVAP, EGR, Fuel Sender, and Rear O2 codes deleted
Speedo and shift points corrected for current tire/gear
Max line psi disabled in case of MAF failure
VATS turned off no relearn necessary - Vehicle Anti Theft System
Fans Activated
For this, the charge was $175 USD. His effort only cost $75 but he had to buy two "credits" for $50 each from the HP Tuner company to "license" the new operating system inside my PCM.
So I think your difficulty will be to find somebody in Belgium that has HP Tuners or a similar program to modify your PCM.
Rick
Thread Starter
Teching In
Joined: Jan 2017
Posts: 22
Likes: 0
Hey Rick - thanks for the info. I'm slowly trying to find someone nearby who has experience with the reprogramming the PCM. I was able to find a dedicated Dutch forum of the Caprice/Impala model but things seem to have died out at lot since 2016. 
have you looked into the eficonnection 24x conversion so you can ditch the optispark stuff and run a ls 0411 ecm? not exactly low buck but more support and tuneability
if you're staying stock it might not be necessary but may be worth a look at this stage
if you're staying stock it might not be necessary but may be worth a look at this stage
TECH Fanatic
Joined: Dec 2017
Posts: 1,476
Likes: 270
From: Bossier City, Louisiana
Hey Dieter,
Don't limit yourself to searching for places that deal with only Caprice and Impala vehicles. I'm certain that there are European groups that support other GM vehicles running later LS style engines that can assist with reprogramming your LT1 engine. I'm fairly certain that HP Tuners is backwards compatible to your LT1 engine.
Rick
Don't limit yourself to searching for places that deal with only Caprice and Impala vehicles. I'm certain that there are European groups that support other GM vehicles running later LS style engines that can assist with reprogramming your LT1 engine. I'm fairly certain that HP Tuners is backwards compatible to your LT1 engine.
Rick
Maybe it's because the 2005 non SS Trailblazer's LH6 has a 24 tooth reluctor as opposed to the 58 tooth reluctor available in 2006. Maybe the operating system on the 2005 Trailblazer is different than the 2006 TBSS.
All I do know is that everyone keeps talking about the TBSS and GTO. Neither of which do I have.
All I do know is that everyone keeps talking about the TBSS and GTO. Neither of which do I have.
You must have miss-posted. This is irrelevant to the op and his post was in 2018. lol
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
