The 'mechanical' ATTESA system was developed for transverse, or front-wheel-drive vehicles and was first introduced with the RNU12 Bluebird in the Japanese market, entering production in September 1987.
The system ran right throughout the U12 series (RNU12/HNU12) and was fitted to numerous U12 models with differing engine and transmission combinations.
An almost identical system is fitted to the RNN14 GTi-R Pulsar and the HNU13 Bluebird and the HNP10 Primera, finding usage in numerous other Nissan models.
From 2000 model year onwards, the system received an update where, as with a typical FWD car, the transaxle now contained a differential that drives the front wheels.
This system is superior in some aspects since the standard operation is FWD there is less power lost due to friction.
The drive for the front wheels comes from a transfer case bolted on the end of an almost traditional Nissan RWD transmission.
The higher the fluid pressure the transfer case is supplied with from the pump, the more the clutch pack engages, enabling the torque to the front wheels to be varied.
Exiting the transfer case, the front drive shaft runs along the right side of the transmission, into a differential located on the right of the engines sump.
[1] To control the ATTESA E-TS system, there is a 16-bit computer that monitors the cars movements 10 times per second to sense traction loss by measuring the speed of each wheel via the ABS sensors.
This will bypass the control system of the ATTESA E-TS computer and lock the transfer case into full 4WD.
Although this is not part of the AWD system, the computer makes use of the same sensors to determine wheel slip and traction.
The 2009 Nissan GT-R uses an updated version of the ATTESA E-TS, which is designed to work with the car's rear transaxle layout.