Late C-4 LS swapper?
Thread Starter
Melting Slicks
Joined: Mar 2003
Posts: 2,512
Likes: 49
From: Franklin IN
Late C-4 LS swapper?
I have a 93, I have questions about the electric part of the swap. I have a wire harness that will run the engine as a stand alone. Id like to pick your brain on how to use the old ECM for the gauges.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
What will require some planning is getting the BCM to "think" that the ECM is still functioning normally.
Thread Starter
Melting Slicks
Joined: Mar 2003
Posts: 2,512
Likes: 49
From: Franklin IN
Pro
Joined: Mar 2000
Posts: 658
Likes: 7
From: Perth Amboy New Jersey
http://tech.corvettecentral.com/2010...-c4-corvettes/
Getting Wired:
We turned the electric over to Jared at Current Performance. He builds complete wire harnesses specific to the application and specializes in integrating the harness to the existing stock systems. Our LS2 required the use of a 2007 Trailblazer SS PCM and transmission module. Jared crafted the wire harness to locate the new PCM in the same location as the 1985 computer. All systems were integrated by blending the original and new harness together. Benefits of his harness include the use of the drive by wire through the stock cruise control switch to maintain fully functional cruise control while disposing of the cumbersome vacuum cruise actuator on the firewall.
Jared included all the appropriate connections and programming to keep the 1985 digital dash functional. The 1985 Computer is completely removed from the system. The only non-function portion is the MPG calculator. This is a small price to pay to have an overall fully functional system not requiring the use of expensive aftermarket gauges. Dakota Digital also makes SGI#5 and #8 boxes for calibrating the tachometer and speedometer as needed.
Le Mans Master
Joined: Feb 2005
Posts: 6,479
Likes: 565
From: Clearwater Florida
..... I'm thinking that you can leave the original ECM/BCM in place and use your stand alone to run the engine ... I don't believe the BCM cares whether or not the engine is running ..... but I haven't swapped anything into a 93 yet .....
Team Owner
Joined: Sep 2003
Posts: 25,384
Likes: 2,736
LCD for speedo/odo I don't believe is an issue that can't be overcome with an ERA/DRA - TACH will likely require also but all of your research depends greatly on your "harness to run" choice. Who's harness & what PCM are you planning on? FULL FUNCTION '93 LCD I'd think difficult ie. OIL & COOLANT TEMP etc.
The more information you mention about "what you've got" will certainly make it much easier to mention what you might expect.
I believe leaving the CCM and using it isn't an issue and is required for ODO/SPEEDO, using the ECM to do the LCD display of OIL - COOLANT TEMP etc. - I'm certainly not sure of.
Last edited by WVZR-1; Mar 16, 2017 at 09:13 AM.
Melting Slicks
Joined: Jul 2011
Posts: 2,605
Likes: 202
From: Trinity FL
Email Paul at Torqhead.
http://www.torqhead.com/index.html
He has successfully gotten an LS1 PCM to communicate with the later C4 Electronics. Everything functions.
http://www.torqhead.com/index.html
He has successfully gotten an LS1 PCM to communicate with the later C4 Electronics. Everything functions.
Pro
Joined: May 2002
Posts: 635
Likes: 6
From: New Jersey
You don't need the old ECM for the LS swap. The only gauges the works off the LS ECM is the Tach and VSS for speedo, and both of those you can program in the LS ECM. The vss connect into the ECM and the ECM has an output that connects to the speedo, but it has to be calibrated in the LS ECM.
Randy
Randy
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski