Basically, for full TTL, the connection pattern from the camera's hot shoe
to the pins on the foot of the flash must conform exactly.

Unfortunately, few of the camera manufacturers have collaborated and/or adhered
to [one] set standard, except for firing the flash; (center pin positive, and side foot ground).

The folks at Paramount Custom Cords may be able to fix-up a solution for you.

http://www.paramountcords.com/faq.asp