Maybe this helps somebody in 2013 ). Mine problem was with that white wire connected to ECM. The solution was to disconnect it from ECM (last time there was 5V output from ECM on the white wire, though there was alternating 5V signal from sensor before - neither way speedo was working with the ECM connected). Now have a spare instrument cluster and a speedo sensor... and a spare wire routed from sensor to speedo...
This is faulty ECM, but since everything else works fine, let it be...