Conversions & Swaps LSX Engines in Non-LSX Vehicles
Sponsored by:
Sponsored by:

A/C through e38 pcm LS7

Thread Tools
 
Search this Thread
 
Old May 8, 2009 | 10:13 PM
  #1  
dsrour's Avatar
Thread Starter
Launching!
 
Joined: Jul 2004
Posts: 223
Likes: 0
From: Potomac, MD
Default A/C through e38 pcm LS7

Has anyone run aftermaret a/c through the E38 pcm?
Looking at the C6 ls7 a/c schematics the A/C request comes to the pcm from the a/c module then bcm via serial data.
So I was wondering if its possible without the bcm or could you use a bcm as well.
The earlier pcms allowed for manual operation of ac.
any thoughts appreciated
Reply
Old May 9, 2009 | 09:36 AM
  #2  
ls1nova71's Avatar
TECH Veteran
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (4)
 
Joined: Jan 2008
Posts: 4,406
Likes: 211
From: Liberty, MO
Default

You would have to also use the A/C module, because to the best of my knowledge there's no way to reproduce the signal that it sends to the PCM via the serial data line. I've been fighting the same problem on my 6.0 conversion. If you could mount that module/switch, and the pressure sensors, it should work.
Reply
Old May 9, 2009 | 03:57 PM
  #3  
dsrour's Avatar
Thread Starter
Launching!
 
Joined: Jul 2004
Posts: 223
Likes: 0
From: Potomac, MD
Default

thanks. looking at schematic looks like ac module goes to bcm then serial data to PCM. I wonder if you could use these modules just for AC. I guess the alternative would be use an ls1 PCM
w 58to 24 convertor
Reply
Old May 9, 2009 | 05:00 PM
  #4  
rsz288's Avatar
TECH Resident
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2008
Posts: 838
Likes: 12
From: Right here, right now!
Default

Originally Posted by dsrour
thanks. looking at schematic looks like ac module goes to bcm then serial data to PCM. I wonder if you could use these modules just for AC. I guess the alternative would be use an ls1 PCM
w 58to 24 convertor
Much simpler to use an LS1 PCM. Which would give you cruise too! The BCM needs the right ignition switch and key just to wake up, let alone do anything. It also validates with the instrument panel and ECM. So if you have a complete take out setup and if you have a buddy who is a GM tech and good with a tech II, that would be a benefit.
Reply
Old May 9, 2009 | 08:22 PM
  #5  
dsrour's Avatar
Thread Starter
Launching!
 
Joined: Jul 2004
Posts: 223
Likes: 0
From: Potomac, MD
Default

Maybe I'll look at using the LS1 pcm. Easier tuning too w/ ve tables.
Which LS1 is considered best these days?
What TB would you use? and DBW pedal?
Dang just finished my E38 harness too!
thanks for the advice
dave
Reply
Old May 10, 2009 | 06:27 AM
  #6  
Jones'n's Avatar
TECH Resident
 
Joined: Jun 2004
Posts: 841
Likes: 2
From: Tampa, FL
Default

Why not just wire the A/C in and bypass the computer?
Reply
Old May 10, 2009 | 07:42 AM
  #7  
dsrour's Avatar
Thread Starter
Launching!
 
Joined: Jul 2004
Posts: 223
Likes: 0
From: Potomac, MD
Default

That would be way too easy. Actually taking advantage of the PCM AC controls makes for a smoother operating system. The PCM does things like bump up the idle before clutch is engaged.
I have it wired this way now with the LS1 and was hoping to do it with the LS7 and E38 PCM as well. The increasing sophistication of the systems with climate control, zoning etc, makes it much more challenging.
Reply




All times are GMT -5. The time now is 07:54 PM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-7
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-8
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-9
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE