VbobV

Howdy - haven't posted much so I'm "new" but trust me I'm only kind of retarded

I just bought the Haltech Rebel LS. I have a built Dart LS Next 427 currrently on the stock pcm in my 2005 ctsv. Runs the stock LS6 accessories,

I'm doing a complete standalone, replacing the dash with the IC7 unit so no need for factory gauges.

2 options
1- keep the PCM so it can talk to the BCM
2- delete the PCM and see if I can bypass the communication errors and still keep basic functions (head/tail lights and indicators, horn, airbags, windows, seat controls, stereo, etc)

First most obvious thing is starting the car. The PCM talks to the BCM to even start the car, but I wonder if I run my own ignition relays and power the BCM whether or not that needs to even happen. If it DOES need to happen, then I wonder how little information I can feed the PCM where it will still communicate with the BCM and not cause errors (ie keeping just serial data lines, ignition)

Most people keep the PCM, lots of people who go standalone and completely remove the PCM also remove the BCM. I'm in the opposite boat where I want to keep BCM. Feel free to yell at me for not using search function, I tried. I lurk here a lot. I've put together a factory five GTM and am pretty familiar with the c5 wiring harness which is very similar to my ctsv - but again in that case I used PCM but no BCM. Just picking the audience to see if you guys have any glaring issues I might encounter before I start this project (and preemptively rip out the PCM). I'll update with cool photos n stuff to help you guys down the road to do something like this. Haven't seen very many good writeups for the CTSV with a Haltech yet. I'm also a surgery resident so it will take me a while to complete

My first test is gonna be disconnecting the PCM and seeing what all still works in the car. This project is 100% happening, and I already sunk the $$ for the Haltech (currently shipping). It will be super cool when it's done. Currently on a pretty intense surgery rotation and studying for licensing exam so I probably won't get around to anything until Sept. Thanks in advance and peace out. I'll update progress in this thread

-Bob

AAIIIC

iTrader: (19)

I don't recall seeing any discussions of installing an aftermarket stand-alone either here or on cadillacforums.com. I would imagine someone has done it, though.

If you aren't already, I suggest joining the "CTS-V1 vs the World" group on FB, and also the "V Series Track/autocross Enthusiasts" group. That latter one may actually be better for your purposes, as there are guys with fully track-prepped cars that may have gone stand-alone.

Oh, and that's a helluva garage you've got there (both in space available and contents)!

VbobV

Thanks man - it's my dad's shop just posted that pic for some eye candy - Had it out there over the winter to do some much needed repairs. Wish it was closer, a lift is so nice to have

I am actually on the FB group as well, seems to be more active

I think I'll run into the same problem with the race forums - most those guys delete the BCM for a track car. I still want the BCM and am less concerned with weight/track times and want to keep my creature comforts. There's really only a few serial data lines from the PCM to BCM, but how important they are to the function of each module is something I don't know....

To be honest, the corvette/camaro guys are the most likely to have done something like this. I saw a very similar post about a Holley setup in a camaro

The real benefit to this haltech package is I can transplant it into any car I feel like down the road.

V1_hitbox

There are a couple guys on the v1 page that are running the standalone piggyback, the guys that did straight standalone deleted everything else.

05CTSV

iTrader: (16)

Back in early 2019 I chucked the factory ecm and harness in the junk pile.

Without the ecm here are some things you’ll loose.
- ABS
- Traction control (wheel speed sensors)
- Speed sensor in the V trans didn’t work
with Holley, not sure about Halltec
- brake lights
- reverse lights
- reverse solenoid control by ecm
- start with the key
- clutch safety switch
- air bag function
- gauge cluster info stuff, oil, temp etc
- fuel gauge in cluster

Things that work even without the ecm
- headlights, low, high, fogs
- all interior power
- door locks with fob
- power seats
- power door locks
- radio

I didn’t care about ABS or traction control, or air bags. The brake lights were an easy fix with a manual switch and connecting it into the wire that controlled the brake light relay. Reverse lights were also easy, it’s a grounded type switch in the trans, just have to tie the switch into the harness to control the relay to turn on the reverse lights. Reverse lockout wasn’t too difficult either, manual rocker switch to send the solenoid power when I need to put in reverse, flip closed to lock out. To start the car I used a relay and a push button momentary switch, key still has to be in the on position. Fans and fuel pump controlled by Holley and relays.

You can keep it simple or make it way complicated, just depends what your end goals are for the car. I don’t post up much on here, but check out what all I did with the Holley on my Instagram 427cadillac

Good luck with the project!

VbobV

Sweet, thanks man

I'm waiting on the Haltech to arrive - they've sent 2 open boxes already and for the money I paid I want a fresh one

Any issues on the ignition circuit? I know the ECM grounds it when you turn the key. And yes, I planned on no ABS/TC but I'll integrate the VSS into the Haltech for TC. Brake wires and reverse signals are all easy enough. I'm also going with the Haltech IC7 Dash so I don't need the factory stuff.

I'll have to look at the airbag diagrams, wouldn't mind keeping those.

-Bobby

VbobV

Officially decommissioning the V. Combination of the speed triple and my fiancees honda are gonna get me to work for a while

Whoever did the fuel lines in this thing ran behind the passenger fender from the engine bay, pretty sure you could sneak into the dash that way but we'll find out. Otherwise thinking I might be able to strip enough off of the stock harness to fit my new one thru the main factory firewall grommet. Final and least desirable option would be to go behind the battery tray and drill my own hole. Gonna be de-pinning the factory stuff for a while, trying to integrate as much into the haltech as possible

Gonna see what happens to the BCM when I unplug the PCM. Probably will go ahead and take off the hood, fenders, bumper to make everything easier

I'll probably post on the facebook group from here on out since it seems like nobody really uses this website anymore lol

05CTSV

iTrader: (16)

Yes, the key won’t crank with the factory ecm removed. I just used the key as a way to turn on the car, and made my own push button start. I believe the airbags also tie into the speed sensor and wheel speed/abs stuff so that the air bags only deploy under certain conditions like over 5mph etc.

SE-R Spec

iTrader: (2)

Here is the write up I did for my terminator X piggyback, should be about the same for your haltech

I probably need to update that thread with some more things I did

https://ls1tech.com/forums/cadillac-...ggyback-2.html