I have got my TH400 in and wired the Park/neutral safety switch together. I used the purple/white and yellow wires. It starts but shows that it is in second gear all the time. This causes the tune to be totally screwed up. It runs great at low rpms but when you start to get above 4000 it screws up. Have I wired the neutral safety switch right or what do I need to do to fix this. Thanks

 

No expert with this but I don't think the park/neutral safety switch would have anything to do with telling the PCM what gear is selected.

I believe the module on the side of the 4l60e is what communicates the current gear selection to the PCM.

 

TTT, having the same issue here, LS1/TH400. Shows its in 2nd.

 

i dont know what to do to make it start tho. where are the wires located and what do i need to do with them?

TIA