Can anyone tell me how the pass key feature works? I'm not doing this to my fiero but in my sons camaro. I have 98 with a 3800, 5 spd, disc brake rear end that I'm swapping into a 94 body. The 98 column is jacked up so I would like to run the 94 column. Is it the lock that senses the resistor or the pcm? I know its not fiero related but if you go on other forums and ask questions about swapping they're stumped. Unless its a CAI or exhaust

The Camaro/Fierbird 3800 PCM can be reprogrammed the same way as the FWD 3800's so just get the PCM reprogrammed to remove the pass key and any thing else you don't want to use from the PCM. Dan

The column 'senses' the key, that is to say there is a contact point inside of the key switch that connects the resistor in the key to the passkey module. In turn the module, when it reads the correct value of the resistor in the key, outputs a signal to the ECM to tell it that everything is ok and start the car.

The passkey module and key are matched, so if you swap out the column, you will need the module (you can always change the ignition switch back to the original so you can use the original key).

...or, just have it programmed out as suggested.

...another method is to install a bypass module to get around the key/module and feed the ECM directly.

OK so the ignition senses the the right key not the pcm? So if I unhook the harness that runs up the column and hook the 3800 harness up to that column it should run?

quote Originally posted by Dementia: OK so the ignition senses the the right key not the pcm?

No...the passkey module senses the "correct" key, the column connects the key to the passkey module, the output of the module connects to the ECM. Correct key = passkey module to turn on the signal that tells the ECM it's ok to start.

quote Originally posted by Dementia: So if I unhook the harness that runs up the column and hook the 3800 harness up to that column it should run?

No, you need to connect the output of the passkey module to the passkey input of the ECM. This will only work if the key you are using matches the module (ie: keep the original column and passkey module and just swap the ECM and make the appropriate connections) - this 'assumes' you are using the same systems: passkey 1 is different from passkey 2 and they are both different from passkey 3, etc.

I am not sure if I am being clear, but we are talking about 3 separte items here: the key, the passkey module and the pcm. The key is in the column, the passkey module is usually under the dash passenger side and the pcm is in the engine bay.

Here is the 94 diagram:


Technically you can connect the A3 output from the passkey module to the 98's PCM pin C1/70 - however, I can not say if the 2 systems are compatiable. ie: if they are both passkey 2 systems, as the wiring diagram for the anti theft is a bit more complicated on the 98 (see diagram below) and it might be the passkey 3 system. In which case you will have to move the 98's key/cylinder and BCM over to the 94 and figure out how to wire it in - be easier to use a bypass module or have it programmed out of the PCM.

Here is the 98 wiring diagram:


Key lower left corner, connects to the body control module (passkey module) pins C2 and D7, the module then connects from D8 to the PCM C1/70 (for the 3.8)