I have two 94 EX coupes, one has a b16 swap/turbo/aem ems the other is a stock automatic sohc. on the b16 car, the speedo and odometer doesnt work. I took out the VSS from it and put it in the sohc and the sohc vss in the b16, and the speedo worked fine in the sohc with the b16's vss. and the sohc's vss didnt work in the b16.

What could be the problem when a working VSS doesnt work? is ity my AEM ems?