is anyone real familiar with a gm pass key system on a 92 bonneville?

Question

this is my friends car. about one year ago the wire broke at the ignition lock cylinder. i bypassed the lock cylinder by installing a potentiometer that i set at the same resistance as the resistor in the key. it has worked fine until a couple days ago. i am having trouble finding any good diagnostic flow charts for this system. i did find a schematic and i see that aside from the starter interupt, the pass key module also has to send a 5 volt signal to the pcm to enable the fuel pump during cranking.
i tried jumping power to the the fuel pump primer connector under the hood and jumped power to the starter at the same to crank the engine(i also had the key in the run position to enable spark and injector pulse). that didnt work.i am running out of ideas.
does anyone know of any common problems or know any way to completely bypass the system?

Answer 1

first of all i am an ex-auto tech, and a current service advisor at a Pontiac dealer. the pass-key system is usually fine once it is bypassed. the problem may be in the enable relay (it enables the
signal to the starter and the ecm) if it is bad, you cannot start the car. it is located at the top of dash ahead of steering column, under the defroster grille, but can only be accessed from the bottom. that part of the system would need checked. also, double check your potentionmeter, to make sure it is not bad. where did you tie into wiring? should be at bottom of steering column wiring where the junction block is. you can check your local library for Chilton or some kind of service manual. you can't check them out, but you can copy the pages.

Answer 2

could be your fuel pump, could be other things, are you sure that you had spark and injector pulse, I will be glad to help you any way that I can, you can email questions to me at [e-mail] but this sounds like something more than pass key system.

Answer 3

Agreed!

Answer 4

I don't know what else you have done, or if you know the system alternatives, but you certainly know more than most.
Herre are a few links, maybe they will help.

http://www.12vp.com/info_resistors.htm

http://www.drdetailshop.com/gmpellet.htm

http://experts.about.com/q/Oldsmobile-Buick-792/gm-vats-system.htm

http://mysite.verizon.net/vze7erz1/id14.html


Good Luck