im putting a 94' lt1 into my ride and need help getting the vats passkey system straight.

all i really need to know is whether the 94 camaros had the passkey1 with a 30hz 50% duty cycle signal to the pcm or is it the newer passkey2 with a 50hz 50% duty cycle.

all i have is the engine harness nothing else... so i either need to get a passkey1 or 2 module with the resistor key to get my fuel pump and injectors working. my other thought was to make a circuit with a 555 timer... but i need to know what systems they put in 94 camaros.

 

'95's have passkey II. Don't know about 94.
http://shbox.com/1/pass_key.jpg

Been a long time since I've built a 555 timer circuit, but I think if it wouldn't be too difficult to change to another frequency, maybe a couple resistors.

If you are smart enough to design/build that circuit then may just want use your brain instead to build your own ALDL cable for $35 from a kit from akmcables.com , download tunercat trial from tunercat.com, buy the tunercat ee def file (definition file for LT1) for $20, get a computer with a serial port or get a serial-to-usb converter, then just program VATS out, wire up the car without the VATS box and without the theft det relay. **As always with tunercat, make sure you always do a read before a write or may burn up the PCM flash chips.

So about $55 versus buying a passkey ii box, resistor for vats, small circuit board and components for 555 circuit that might not work.

 

Agreed, just tune vats out and remove it from the harness + 1