It will be used system "4wd" or "2wd" without use ABS......
What I'm saying is the attesa system need to use speed sensors from the 4 wheels in order to activate the FWD portion of the AWD system.... if you open the AWD transmission transfer case, you will find a clutch drum inside that make a couple of chain turn your output shaft going to the front diff.... in normal driving condition, the "clutch drum" is spinning freely, making it basicly a RWD, that is why you can run a GTR on a RWD dyno.... When the ATTESA controle module (which is wired to all four speed sensor) detect rear wheel spinage, it activate the clutch drum in the transfer case and thus, transfer some of the power to the front wheel, with a maximum of 50/50 power between the front and rear axle...the ABS speed sensors are not to use ABS brake, but to use as input data for the ATESSA controle module for it to control an hydrolic pump to lock/unlock the the clutch in the bell inside the transfer case
In other words, if you don't connect an ATTESA controle module to 4 speed sensor, you'll end up with a RWD fitted with a transfer case that will be disconnected from the transmission permenantly, thus making it RWD and if you activate permanently the clutch in the transfer case by jumping the power on the pump, you will turn the system into a 4wd without a center diff, thus making it inefficient on dry pavement/street.... the beauty of the ATESSA system, is that it's not on/off like a 4x4, but it's constantly adjusting power biais between rear and front axle over changing driving condition...
Tom
