I am doing an OBD2 convbersion on my 97 Z. I want to make it plug and play so i can go back to stock for emmissions. All i want to do is have to swap out the computers.

Through searches on this site i have figured out that the only thing i really need to do to the PCM is wire in a a 3.9k ohm resistor between ground and pin 22 of the blue connector.

Does this mean i take a the 3.9K resistor and ground out that pin with it to any ground on the car? Is this right, i dont really want to fry this computer. Any thing else than needs to be done?

 

When you open your PCM up, on that same board is the grey colored connector. If you solder that resistor to the 22 of the blue connector then connect the other end to pin 32 of the gray colored connector that is a PCM ground. The gray colored connector is on the same circuit board that you are connecting the resistor to. Doing that you won't have to bring any wires out of the PCM. Or you can go to the nearest case ground on the circuit board. Be sure to properly insulate your resistor wiring.

 

Thanks for your help, i think i understand it now.

 

This is for the knock sensor, right?

 

Yes it is. The 96 and up PCM uses a KS with a 100k ohm shunt resistor while the earlier cars uses a 4k ohm resistor.

 

Is that all that is required to convert one for plug and play. What wattage resistor should I use? I am doing this also and I appreciate all of the information.
Thanks,
Botch

 

1/8 watt is more than adequate for this.

 

Thanks. Done and it works!

 

OK, stupid question time...How do i tell which pins are 22 and 32? Do they go in a certain order or what?