ECU swap to gain ATRAC?
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confused buy your ?if the wiring is there and you have the locker just put the switch in and your done. if you dont have the locker. Im not sure......if it is even gonna work, some one that now's these system will chime in a correct me in sure .Good luck
Go over to FJCruiserforums and search.
Short answer: No, you cannot just swap a control unit out of a FJC that has A-TRAC into a non rear locked vehicle and get A-TRAC.
Only guy who actually spent a lot of time researching installing A-TRAC into a non rear locker 4x4 was a guy in Puerto Rico. After all of his research, i believe the answer was no. It's not easily possible and certainly not as simple as swapping a control unit.
IIRC, i believe you need part of the wiring and what not of the rear e-locker control as it connects with the A-TRAC controls as well. I think he hacked up some of the wirings to the point that TRAC sort of worked in 4LO, though, it wasn't near as good as A-TRAC.
http://www.fjcruiserforums.com/forums/4x4-off-road-tech/61565-add-trac-non-locker.html
Here is the post on how to get "TRAC" to work in 4LO since having A-TRAC isn't possible.
"To read the original full thread and post questions/comments on this topic, please go to http://www.fjcruiserforums.com/foru...75347-4lo-trac-hack-trac-non-locking-fjs.html
Disclaimer:
I, this forum or anyone posting in this thread cannot be held responsible for any damage that might occur to your vehicle because of this modification. By modifying your own wiring harness you take full responsibility of any damage, injury, etc… that might occur.
Does it work, Yes! How does it compare to A-Trac, only time will tell...
Intro:
All of you know by now that if you didn’t get an FJ with a rear Diff Lock, you automatically didn’t get A-Trac. Now surprisingly, the locker has nothing to do with A-Trac, its just that Toyota apparently thought that if you don’t need a locker you have no use for A-Trac ether.
Looking at the difference between a Locking FJ and Non-Locking FJ you will find only one difference that has anything to do with A-Trac, which is the Brake Computers Part Number (The one mounted to the Brake Booster).
All the wiring, sensors, actuators, etc… are the same because A-Trac uses the same system as VSC, ABS, and Trac. So the only difference is programming.
Now since Toyota has not released the Re-Flash for the Brake Computer (Dealer theory is just replace the unit) and a new Brake Computer is as much as a ARB Locker (If you have the money for a Air Locker, than by all means, go for it, I will… sooner or later) there is really no good way to get A-Trac. So my theory was converting Trac into a from of ‘A-Trac’, different problem, same end result…
Thanks:
First of all, let me say THANK YOU to some members who have helped without even knowing it; because of their previous research, posts and answering some questions, I was able to find a way to do this.
Thank You to: PRCruiser, Kansas Law Dog, Tranman, Homdad, and Tibaal89
Theory:
Trac is a from of A-Trac with one major difference: Trac only works in 4Hi (HL) and A-Trac only works in 4Lo (LL). Contrary to most peoples believes, Trac does NOT control RPM in 4Hi (HL), only in 2 wheel (H) drive.
Actually making Trac work in 4Lo (LL) is as simple as bypassing the 4Lo (LL) switch for the Brake Computer and ECU.
One question remains:
Does Trac control the front wheels or just the rear?
As of right now, I don’t know. This will require some more testing. No matter what, I believe having Trac on the rear wheels in 4Lo is better than nothing.
How:
The mod is actually very simple. All your doing is interrupting the ground signal from the 4Lo (LL) indicator switch to the Brake Computer and ECU, therefore making them think your still in 4Hi (HL).
Mod:
Look under the dash on the passenger side, you will see one of the main harnesses running through the firewall. Taped to it you will see a Blue Jumper (B45).
In this jumper are 3 White/Blue (W/L) wires, you need to unpin (or cut, or cut and put a switch in, which ever you prefer) the wire on pin 9.
If your looking at the wire side of the connector, with the release button on top, it will be the 3rd W/L wire (the one all the way to the passenger side). MAKE SURE you get the W/L wire on pin 9 if you get one of the other 2 you will have a X-Mas Light Dash!
That’s it! Your done!!!
This is a picture of mine after the mod. I put a switch in line so I could test it, the brown wire goes straight into pin 9. The 'aftermarket' W/L wire goes to the wire that used to be on pin9. Hope that helps...
The way you know its ‘Engaged’:
Go into 4Lo (LL). Usually the car with the swirly marks will turn on, telling you that Trac is no longer active. If your in 4Lo (LL) and that light does not come on, the mod worked and you now have 4Lo-Trac. Trac will disengage when hitting the brake and/or clutch.
Obstacle Example:
In January of 2008 I attempted a steep hill climb on lose dirt, some rocks and large ruts. I got stopped at a point where passenger font and driver rear where just spinning. I tried for 30 minutes, different lines, but the truck just got into a worse position every time. So I gave up and backed down the mountain.
In December of 2008 I attempted the same hill climb, I again got stuck at the same spot, again same problem (2 wheels spinning). I then flipped my switch to turn 4Lo-Trac on, shifted into 3rd (seams to work better) and kept a steady foot on the gas. With some guidance of Homedad, the truck started moving, the brakes where engaging like crazy, my Trac light where blinking like crazy and the truck just kept on going."
Short answer: No, you cannot just swap a control unit out of a FJC that has A-TRAC into a non rear locked vehicle and get A-TRAC.
Only guy who actually spent a lot of time researching installing A-TRAC into a non rear locker 4x4 was a guy in Puerto Rico. After all of his research, i believe the answer was no. It's not easily possible and certainly not as simple as swapping a control unit.
IIRC, i believe you need part of the wiring and what not of the rear e-locker control as it connects with the A-TRAC controls as well. I think he hacked up some of the wirings to the point that TRAC sort of worked in 4LO, though, it wasn't near as good as A-TRAC.
http://www.fjcruiserforums.com/forums/4x4-off-road-tech/61565-add-trac-non-locker.html
Here is the post on how to get "TRAC" to work in 4LO since having A-TRAC isn't possible.
"To read the original full thread and post questions/comments on this topic, please go to http://www.fjcruiserforums.com/foru...75347-4lo-trac-hack-trac-non-locking-fjs.html
Disclaimer:
I, this forum or anyone posting in this thread cannot be held responsible for any damage that might occur to your vehicle because of this modification. By modifying your own wiring harness you take full responsibility of any damage, injury, etc… that might occur.
Does it work, Yes! How does it compare to A-Trac, only time will tell...
Intro:
All of you know by now that if you didn’t get an FJ with a rear Diff Lock, you automatically didn’t get A-Trac. Now surprisingly, the locker has nothing to do with A-Trac, its just that Toyota apparently thought that if you don’t need a locker you have no use for A-Trac ether.
Looking at the difference between a Locking FJ and Non-Locking FJ you will find only one difference that has anything to do with A-Trac, which is the Brake Computers Part Number (The one mounted to the Brake Booster).
All the wiring, sensors, actuators, etc… are the same because A-Trac uses the same system as VSC, ABS, and Trac. So the only difference is programming.
Now since Toyota has not released the Re-Flash for the Brake Computer (Dealer theory is just replace the unit) and a new Brake Computer is as much as a ARB Locker (If you have the money for a Air Locker, than by all means, go for it, I will… sooner or later) there is really no good way to get A-Trac. So my theory was converting Trac into a from of ‘A-Trac’, different problem, same end result…
Thanks:
First of all, let me say THANK YOU to some members who have helped without even knowing it; because of their previous research, posts and answering some questions, I was able to find a way to do this.
Thank You to: PRCruiser, Kansas Law Dog, Tranman, Homdad, and Tibaal89
Theory:
Trac is a from of A-Trac with one major difference: Trac only works in 4Hi (HL) and A-Trac only works in 4Lo (LL). Contrary to most peoples believes, Trac does NOT control RPM in 4Hi (HL), only in 2 wheel (H) drive.
Actually making Trac work in 4Lo (LL) is as simple as bypassing the 4Lo (LL) switch for the Brake Computer and ECU.
One question remains:
Does Trac control the front wheels or just the rear?
As of right now, I don’t know. This will require some more testing. No matter what, I believe having Trac on the rear wheels in 4Lo is better than nothing.
How:
The mod is actually very simple. All your doing is interrupting the ground signal from the 4Lo (LL) indicator switch to the Brake Computer and ECU, therefore making them think your still in 4Hi (HL).
Mod:
Look under the dash on the passenger side, you will see one of the main harnesses running through the firewall. Taped to it you will see a Blue Jumper (B45).
In this jumper are 3 White/Blue (W/L) wires, you need to unpin (or cut, or cut and put a switch in, which ever you prefer) the wire on pin 9.
If your looking at the wire side of the connector, with the release button on top, it will be the 3rd W/L wire (the one all the way to the passenger side). MAKE SURE you get the W/L wire on pin 9 if you get one of the other 2 you will have a X-Mas Light Dash!
That’s it! Your done!!!
This is a picture of mine after the mod. I put a switch in line so I could test it, the brown wire goes straight into pin 9. The 'aftermarket' W/L wire goes to the wire that used to be on pin9. Hope that helps...
The way you know its ‘Engaged’:
Go into 4Lo (LL). Usually the car with the swirly marks will turn on, telling you that Trac is no longer active. If your in 4Lo (LL) and that light does not come on, the mod worked and you now have 4Lo-Trac. Trac will disengage when hitting the brake and/or clutch.
Obstacle Example:
In January of 2008 I attempted a steep hill climb on lose dirt, some rocks and large ruts. I got stopped at a point where passenger font and driver rear where just spinning. I tried for 30 minutes, different lines, but the truck just got into a worse position every time. So I gave up and backed down the mountain.
In December of 2008 I attempted the same hill climb, I again got stuck at the same spot, again same problem (2 wheels spinning). I then flipped my switch to turn 4Lo-Trac on, shifted into 3rd (seams to work better) and kept a steady foot on the gas. With some guidance of Homedad, the truck started moving, the brakes where engaging like crazy, my Trac light where blinking like crazy and the truck just kept on going."
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If you had the locker, all you would need is a $50 switch.
1911
chupacabra
Way too much trouble for you; A-Trac not worth it IMO. Learn and practice left-foot braking, you will get the same result for free. 
