I was wondering if anybody knows how to bypass the vats on a 07 ecotec and harness. The way I see it is the key switch communicates with the vats module with a specific resistance. The vats module tells the bcm every things ok you can start. Does it do this through ground or hot? The bcm then tells the ecm your good to go. So what I want to know is does the ecm see any other input other than the ground or hot from the bcm during the start up process?

I got my ecu flashed and turned the vats off.

Yeah, I know the vats can be deleted, this one will be going to the dyno and reflashed using hp tuners. I am just curious to why it can't be bypassed using a voltage or a ground to the ecm. Unless the gmlan serial data + - wires do the talking to the ecm from the bcm.

It uses class 2 seriel data comunications to talk to other modules. Basicaly computer talk. You can't trick it with a voltage signal or ground.

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Turbocharged Ecotec,vanogon midshift,Berrien WoodsBuggy wagon.

i dont know about the ecotecs but i do know you can build a box for a ls1 for about $15 from radioshack to fool the vats.im not sure the vats work the same but on a ls1 it needs a certain voltage and certain Hz to let it run.not sure if it would work but you could ask on a ls1 forum or someone selling one on ebay.

That is what I was thinking just not sure. We are doing this harness ourselves. I need to know if the gmlan serial data wires will just be wired to the obdll port for communication since the bcm and tcm are gone.

Yeah pretty much. Just wire the aldl as it would be in the original car.

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Turbocharged Ecotec,vanogon midshift,Berrien WoodsBuggy wagon.