Can anyone provide information on the LE version of the All-Trac.

There is two versions for the All-Trac in North America :

DX (DLX)
SR5

Here.. try these...

http://e-automobiles.blogspot.com/2008/12/1994-toyota-previa-all-trac-le-review.html

http://en.wikipedia.org/wiki/Toyota_Previa

this could shed some more light on the centre diff lock's function as well..

http://en.wikipedia.org/wiki/All-Trac

1988 Toyota Camry

Reflecting an industry trend, Toyota gave Camry an All-Trac sedan with permanently engaged all-wheel drive. The AWD system split engine torque 50/50 front/rear; it lacked separate low-range gears like a 4WD truck, but had a mechanical center differential that could be locked for maximum traction in slippery conditions via a dashboard switch. The All-Trac came only in LE trim and with manual transmission.

The all-wheel drive Camry All Trac sedan was new for the 1988 model year.
©2007 Toyota via Wieck
The all-wheel-drive Camry All-Trac sedan was new for the 1988 model year.

Other models returned from '87 with detail trim and equipment changes, including standard outboard shoulder belts for the rear seat and an available package with power windows and door locks. The LE's power sunroof was newly available for Deluxe models.

Following Honda's lead with its American-built Accord, Toyota began building some Camry sedans at a new plant in Georgetown, KY -- the company's first "transplant" factory. This was in line with Toyota's aim to "build where we sell," and would have long-term implications for Toyota and the entire U.S. auto industry.

At about the same time, the Camry line again expanded, this time with V6 models offered as Deluxe and LE sedans and an LE wagon. The engine, a twincam 2.5-liter with 153 horsepower, would be shared with the Camry-based ES 250, the junior model for Toyota's new luxury Lexus brand launched for model-year 1989. In another first for Camry, V6 LEs offered optional antilock brakes (ABS).

1989 Toyota Camry

The 1989 Toyota Camry saw few alterations, a change of pace after two busy years of developments. The All Trac sedan could now be ordered with automatic transmission and, like front-drive LEs, optional ABS. But the model remained a tough sell, and Consumer Guide noted, "High price and the resulting prospect of limited sales have ruled out a V6 All Trac Camry, according to Toyota."

http://auto.howstuffworks.com/toyota-camry2.htm