Floorman279

iTrader: (11)

everrytime i search im finding info about converting the rear ends itself. im switching cars and at the end of the day want my car to be a 3 channel. i will be buying an aftermarket 3 channel rear so no conversion necessary here, just need to convert the car over. if i end up getting a 4 channel car, how do i convert that car to a 3 channel? obviously a new 3 channel abs module, new lines running to the back, but.....

1) is there any kind of electronic reprogramming necessary? is everything electronic operated off of the 3 channel abs module? will the car communicate properly with the 3 channel module? will that big connector that goes to the 4 channel module plug into the 3 channel and still work correctly?

2) what do i do about the rear speed sensor harness? obviously i source a 3 channel harness but if i plug that into the connector next to the fuel pump connector, will it work correctly?

Floorman279

iTrader: (11)

The reason why I am asking is because I am tired of my current setup and I'm completely switching vehicles. My current car is a 4-channel however with my aftermarket rear I cannot get the 4-channel to function properly. So in a perfect world my next car will have a abs only AKA 3 Channel but finding 3 Channel Cars can be tough to find depending on what trim level you are looking for and if it's stick or not. What I can start doing is looking at wiring diagrams on traction control cars versus non traction control cars and seeing what I can find out as as far as the actual wiring goes. I had one sponsor start telling me that no it can't be done but then as I'm explaining my things then they start going on about how it's inside the actual PCM itself which I find that extremely extremely hard to believe and even if it was I'm sure that a simple flash of some kind would be able to restore it from it's current settings just like you do when you have an automatic to a manual conversion or vice versa. So if anybody here has dug into this or can lead me into any insight please let me know. I'm not concerned with replacing all the hard Parts I understand what will need to Steve replace their what I'm concerned about is yes the harness from a three or four Channel car will probably plug in to either car but are the pinouts on the car going to be the same is one of my concerns.

I'm not just switching cars for this reason there's a couple other reasons but this just happened to be one of those my next time around I want abs instead of nothing at all. So I'm finding a lot of 4-channel cars that fit in my bill and my theory is there can't be a whole lot to this.

Floorman279

iTrader: (11)

Also these are mass-produced cars trying to be as cheaply done as possible I can't see them doing any internal wiring differently other than Maybe how the wires enter the connector at the ABS module. If those wires go from the ABS module to the PCM are different then that's going to be an issue with pinning out everything but I can't really see that being possible from a financial standpoint on GM

Floorman279

iTrader: (11)

I'll keep just replying to myself haha. Anyway after thinking about it the ABS module has to be connected to the PCM because how else would it tell the car that it needs to pull timing in a traction control situation. That still doesn't mean though that it I would need the PCM connected properly to control the ABS. The module does that all on its own. Not to mention the PCM is responsible for Illuminating the ABS related dash lights

FirstYrLS1Z

iTrader: (4)

The thread has 150 views and nobody is replying because what you want to do has not been accomplished. I work on rear ends and constantly input to threads concerning 3 channel ABS and 4 channel ABS & TC. Converting a rear end from one to the other is possible and in converting a 4 channel rear end to 3 channel requires machining. But converting an entire car has yet to be done. Those that wanted to do it, after finding out the incredible complexity, just end up not having ABS or ABS & TC and have standard pre-ABS brakes with the dash lights illuminated.

pdxmotorhead

Is the TCS brake controlled (IE sets the brakes to stop wheel spin)
Or is it pulling timing to reduce power?

I've seen it done both ways,, or like BMW with their extra throttle plate on DBC cars..

Floorman279

iTrader: (11)

ours is a combo of braking, and timing, but mostly timing.

first year, im looking at it the wiring diagrams right now and there is only 1 wire in the entire 4 channel abs module connector that is different between the 3 and 4 channel....granted the 4 channel has a ton of extra wires, but still. what road block am i goona hit that i haven't realized?

http://bowlingss.com/DownLoads/Servi...al/ANTILO2.PDF

if u have the time to look, scroll very far down to find diagrams......nothing goes to the ecu

Floorman279

iTrader: (11)

seriously, it cant be very complex.....it was a $500 add on, i read somewhere that nothing sends direct signals to the tach, it all goes through the ecu first......this diagram says module goes direct to cluster....

is it safe to say from an electronic standpoint, at the end of the day, if i make the 4 channel harness, match everything to the 3 channel harness, that takes care of the connector and its just hard parts.....

only 1 issue im seeing, the 4 channel connector has some stuff going to the TPS then connecting to the pcm, those are signals from the pcm and used when the pcm wants to control the TPS correct? those arent inputs? as long as those arent inputs we should be good


the LF wires are the same pinouts on each, and the one for the RF is in the same spot. the other RF on the 3 channel is DK green spot 3. on the 4 channel it is DK green spot 4. since spot 4 is unused on the 3 channel, i just pull DK green out of 4 and put it into spot 3.

as far as the rear wheel single sensor the black and the red wires for the LR wheel speed sensor are in the same pinout. i get a 3 channel harness that connects to the axle, i see which prongs the black and red connect to on the car, and check to make sure that they match up correctly to the axle harness and im good to go. that completes all the wiring for the the abs module

Floorman279

iTrader: (11)

Still waiting for anyone to chime in telling me this isn't possible so that I don't waste Time and money on this

FirstYrLS1Z

iTrader: (4)

ABS & TC started in 1995 with the 4th gens. That's 23 years and nobody has posted a successful project. Yes it can be done to rebuild the car as GM would have built it, BUT at what cost, time, and frustration. Abandon the project, cut your losses early, and buy a LS1 4th gen with ABS only. Harsh recommendation but that's how I see it. When you get those CD's I mailed you, look it over and post back your thoughts.

Floorman279

iTrader: (11)

i just dont think many people have desired this, many people just ditch it altogether.

i honestly haven't found a reason why this cant work. the wiring is almost identical, brake masters/ and boosters are the same. get an abs module for 50 bucks, and new lines to the rear. source the rear harness and the sensor, maybe 100 if that for both......make my own brake lines for cheap or source a 3channel donor......what am i missing here? not being a smart ***. i have looked over all the major cities on craigslist, auto trader etc.....i have found 10 black on black m6 ss cars that are stock are barely modded. only 1 of those is 3 channel and its 10 hrs away......thayts why im considering this project

silverboy02

iTrader: (7)

Were you ever able to get the car converted to 3 channel?

pdxmotorhead

One reason is no shop with any sense would touch it,, unless they had a 15Mil umbrella liability policy.
Changing the type of TC is the kinda thing a lawyer would eat up.
The ABS control modules are not the same part number are they? I cant picture not needing 4 signals if the electronics is designed for 4.
One option would be if its a 4 channel run both wires to the diff and install an extra sensor on the same trigger wheel.
If your running a locker or a spool it would be the same as having the sensors on the axle ends.
You would just have to make sure the trigger wheels tooth counts are all what the system expects to see.

Floorman279

iTrader: (11)

I had an idea pretty sure would work but I abandoned the thought