My understanding is the harness supplied 5 volts for the MAP. The output of the MAP center terminal shouldnt change in voltage when tied into the MAT input. The three bar will read 1.6v approx key on. You dont need to supply the 3 bar with 5v since the TTA already does this through the factory harness.
So a simple jumper from MAT to MAP signal should work no?
There is a plug behind the passenger side has green, black, gray.. its by the VSS module behind the map pocket that has the green wire=MAP signal.
See if you can reach Bob Bailey and ask him if the input on the ecm is ok to use 0-5v on the MAT. If so.. simple jumper wire.. badabing.
HTH