My 98 Cav 2.2 auto hadn't been tripping the starter relay lately, but it would turn over and run after a few tries if I hotwired it or manually closed the starter relay. I assumed the ignition switch was faulty and installed a simple starter button to the so that the key is still necessary. It seemed to work because the car started and ran several times in a row, but now it's acting up.
It will always turn over now and sometimes it runs fine, but other times it will just keep cranking or die after a couple of seconds. This sounds like a passlock problem to me... except that it's intermittent! Did I tap the wrong wires, or do I need to bypass the passlock even though I'm still using my key? I used the pink switched "Ign 1" for the supply to the yellow "starter" wire, just behind the ign switch plug. This runs to the starter relay, installed as one of the GM recalls.
I really need this POS to run again because I go back to college in a couple of days. Thanks!
I'm not a pass-lock expert by any means. However, I did install a couple remote starters on my sisters cars so I worked with it.
I learned that as the key is switch on, the ECU reads the resistance code which must be given within a certain window of time. Also the gauge cluster is part of this as the car will not run without it plugged in.
My thought is that maybe you're having problems because you are using the push button and never removing the key so the if the resistance value changes or rotates like a "rolling code" it will not learn the new code since you are not removing the key. Of course this could be complete bull - its just a thought. However, pull the key, then put the key in and rotate ignition forward and try push-button. Let me know...if it works every time then we both learned something either way.
What you could do is install one of $10 pass-lock bypass modules this may permanently remedy the situation.
If it dies after a few seconds, it's Passlock. If it's doing something else, then you've got other issues (as well, it sounds like).
You need a working lock cylinder, in order to install a bypass module... because the bypass learns the R-code generated by the lock cylinder when you put the key in, then simulates it. If the cylinder is busted, a bypass is no good on it's own.
Are you still using the actual crank part of the key switch when you're cranking the car?
What I'm trying to say is that if you're pushing the button to crank the car and at the same time using the key switch like you normally would to crank the car, is it starting the car and letting it run?
If so, then your timing on the key switch along with the push button crank switch aren't timed right.
I've been running this for about 9 years now when the ignition switch went bad on my key switch and wouldn't crank the car.
So I hotwired it with a pushbutton so that when I needed to crank the car, I'd use the key switch like I normally would but when it came for the actual cranking of the car, I'd use the pushbutton simultaneously with the key crank position to crank the car.
Initially, I had passlock issues but over time, I got the timing down so that I never have an issue with cranking the car with the push button start.
I've had other people try to crank the car and they can't get it to crank because they can't time it right for it to not go into passlock.
So if your setup is similar, try to work with the timing of the keyswitch along with the pushbutton to make it work every time.
And I'm not really understanding this resistance reading of the key in the ignition and the ECU seeing this resistance.
There's nothing like this on the Jbodies but on some of the other GM cars, there is an actual resistor based device in the key that the ECU reads to recognize the owner of the key.
This keeps the thief from using a key that fits the ignition but has the wrong resistance to crank the vehicle.
Misnblu.com
Newbie member since 1999
Thank you Dave and JBO! 
Misnblu wrote:And I'm not really understanding this resistance reading of the key in the ignition and the ECU seeing this resistance.
There's nothing like this on the Jbodies but on some of the other GM cars, there is an actual resistor based device in the key that the ECU reads to recognize the owner of the key.
This keeps the thief from using a key that fits the ignition but has the wrong resistance to crank the vehicle.
From what I understand... it's a hall effect sensor in the end of the lock cylinder, and the resistor itself is part of the cylinder not the key. There's a switch inside the lock cylinder that closes once the key is fully rotated.
I haven't actually taken one apart to see how it works, though I really should.
Hmmm, quite interesting John and never knew this.
Maybe that's what has failed in my situation as when I turn the key to crank, it does nothing.
But all of the functions of the key switch work perfectly.
It's not like I want to repair it after all these years though.
Thanks John.
Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!
It's separate from the contacts for powering the starter motor, from the wiring diagrams... which you replaced with the push-button anyway. If you're turning the key all the way, then hitting the start button - you're completing the cycle as the car would expect.
If you were trying to start the car with a push-button WITHOUT turning the key as well (to send the R-code for the Passlock), like the OP is trying to do... then that would explain the problems.
Without reading the Body codes set... you'll never know for sure. A simple powertrain scan tool won't read body codes, nor will it set a check engine light.
Got it.
Yeah, I'm doing exactly what you described in the first statement and if I just press the pushbutton, all it's going to do is just turn over the engine.
But the engine does not try to run at all in my situation when I have it in the run mode and push the button. All it's going to do is turn the engine over with nothing more happening until you actually turn the key all the over to start the car.
It works and couldn't be happier with the makeshift pushbutton start. And it's all because I'm too cheap to buy another key module assembly. lol
Thanks for the information John.
Misnblu.com
Newbie member since 1999
Thank you Dave and JBO!
Vats had the resistance value in a chip on the key. Passlock has a hall effect switch that senses the rotation of the key. If they cylinder is rotated and the lock mechanism isn't at the correct spot, no start.
HP tuners is your friend in this case.... if you disable vats wouldnt that fix his issue?
heavyclutch wrote: Also the gauge cluster is part of this as the car will not run without it plugged in..
My 2000 Z runs without the gauge cluster, when i was doing the rebuild earlier this year, i had the dash ripped out, and i was able to move my car around the garage to driveway and whatnot without the cluster installed...
True enough... 95-99 cars need the cluster, as it controls the Passlock function. 00-05 cars need the BCM plugged in, as it controls the Passlock on the later models. The cluster is not necessary on the 00-05 cars.
That's because 95-99 cars are Passlock 1, and 2000+ are Passlock 2.
