I have an 01 tacoma prerunner 3.4l automatic transmission with ect button. I have removed the factory cluster do to it not fitting in the stock location anymore do to roll cage. I have installed aftermarket gauges except for a speedometer since I'm going gps speedo. When I plug my scan gauge 2 in it reads speed. But it is still not shifting automatically. I can shift it 1-3 manually. I'm sure it's an electrical issue I'm over looking. I have all the factory plugs still behind the dash and been splicing in to the harness as needed to make gauges work. Any additional input would be awesome.

Thanks

 

AFAIK the trans ecu gets it's speed signal from the speedo cluster. The transfer case sends signal to cluster and cluster to ECU. Try plugging in factory cluster temporarily.