4Runner/FJ Cruiser SCU Compatibility

[BlackWorksInc]

So I don't remember where I posted this, but a while back I hypothosized that you could use the SCU (Skid Control ECU) out of an FJ Cruiser in a 4Runner to gain the more aggressively programed "ATRAC."

I finally got a used FJ Cruiser to look over and to my dismay they changed the SCU location when they built the FJ Cruisers & coincidentally the 4Runners.

As I stated before the '06 4Runners use a different style Hydraboost unit than the previous models and this is shared with the FJ Cruiser as well. The ABS/TRAC/SCU has been combined into one control module/solenoid pack on the newer Hydraboost units where as on the older ones the SCU was seperate and located under the dash behind the Fuse Panel.

In short, unless you were to replace the module/solenoid pack on the side of the Hydraboost unit, you can swap SCUs and doing so would be more trouble that its worth. So unfortunately my idea for a "plug & play" mod to gain more aggressive ATRAC functionality in this respect is a dead end.

 

[eddiebx]

Forgive me for asking a dumb question, but exactly how is it more aggressive?

 

[BlackWorksInc]

The FJ Cruiser is designed more for off-roading than the 4Runner is, the 4Runner has a more "tame" ABS/VSC/TRAC Set-up than the FJ because of this. The hardware is the same, its just the software values are a little different between the two. In the FJ Cruiser, the ATRAC kicks in more easily than in the 4Runner and more agressively; ATRAC and TRAC are essentially the same thing and the line between them is very fuzzy. It doesn't help that Toyota halphazardly throws the two around almost interchangably from '06-ish up.

Basically, the point being that lets say you're locked, in 4Lo, and the 4Runner's got a wheel in the air and another slipping. When ATRAC kicks in it will utilize the ABS hardware to create a quasi-locking diff effect by locking the wheels up. The 4Runner might not do this as quickly or readily as the FJ Cruiser because the parameters for wheel slip and so on are "looser" than the FJ Cruiser's more agressive "off-road" tuned ATRAC.

In short, the idea for the mod was to utilize Toyota's existing infrastructure for their TRAC system but use stricter parameters to force ATRAC to kick in easier and work a little harder as a sort of in between or alternative to investing in a full blown locker.

 

[Angry_shoe]

Old thread but I wonder if it could be beefed up with a swap from another S-ECU from another 120 platform rig? Has anyone heard anything?

 

[andreylights]

So I don't remember where I posted this, but a while back I hypothosized that you could use the SCU (Skid Control ECU) out of an FJ Cruiser in a 4Runner to gain the more aggressively programed "ATRAC."

I finally got a used FJ Cruiser to look over and to my dismay they changed the SCU location when they built the FJ Cruisers & coincidentally the 4Runners.

As I stated before the '06 4Runners use a different style Hydraboost unit than the previous models and this is shared with the FJ Cruiser as well. The ABS/TRAC/SCU has been combined into one control module/solenoid pack on the newer Hydraboost units where as on the older ones the SCU was seperate and located under the dash behind the Fuse Panel.

In short, unless you were to replace the module/solenoid pack on the side of the Hydraboost unit, you can swap SCUs and doing so would be more trouble that its worth. So unfortunately my idea for a "plug & play" mod to gain more aggressive ATRAC functionality in this respect is a dead end.

What about post 06 4runners and fjs - is the ecu properties any different depending on the production year?

PS necromancy of the tread, I know %)