1998 K1500 5.7 starts then immediately dies

[618 Syndicate]

The only reliable method of removing the passlock is to tune it out.

 

[df2x4]

Your resistor is probably still fine, my money is on something else in the system failing. You could remove the resistor from the circuit and test it with a multimeter if you really want to know if it's still within spec.

 

[HotWheelsBurban]

What has me a little stumped is the bypass I did 10 years or so ago on my C2500 is still working. I bought a "kit" on ebay which was basically instructions and a resistor. The resistor, according to the info that came with it was tested to be 2,750 ohms, wattage not stated. The resistor I put in the suburban was from a pack of ten I bought on amazon, 2.2K ohms, don't remember the wattage. I'm wondering if I have a "hardier" resistor in the C2500 than in the Suburban and that's why no problems (yet). I will say that after I did the bypass on the 2500, the "security" light is always on.

From what I have read and heard, the security light will stay on with the PCM delete. That's how it is on my '99 Burb; I had that done in October 2019 and it's been fine since. Starts like it's supposed to, even after sitting for a few weeks. Got a fairly new and big enough battery and newish starter,( replaced at the same time). I have also heard that the resistors eventually change resistance over time and then that trick no longer works, because the resistance value is no longer correct.
We went round and round with the Burb, I was about ready to shoot it or sell it. I tried every "relearn procedure" online and on YouTube, and most worked once or twice, then back to square one. Our Burb would be fine and dependable for several days, and then not start and stay running, of course it acts up when someone has to get to work!
That problem led me to this forum,after much google -ing and not much information from SilveradoSierra.com which was primarily for the later800/900 series trucks. I learned about the various remedies, but didn't want to hack up the wiring, so I researched the computer tuning programs. Was referred to a shop in the suburbs of Houston, Texas that does a LOT of tuning and mods on LS platform vehicles. When the Burb finally started and stayed running, after a solid month of me and my brother trying it 3/4 times a day, I swear it was like the Burb was asking me "hey mom is this what I'm supposed to do?",the way it started running was like it had forgotten how! Once the computer got everything set, it ran fine, and we took it to this shop. An hour and $250 later, problem solved.

 

[someotherguy]

What has me a little stumped is the bypass I did 10 years or so ago on my C2500 is still working. I bought a "kit" on ebay which was basically instructions and a resistor. The resistor, according to the info that came with it was tested to be 2,750 ohms, wattage not stated. The resistor I put in the suburban was from a pack of ten I bought on amazon, 2.2K ohms, don't remember the wattage. I'm wondering if I have a "hardier" resistor in the C2500 than in the Suburban and that's why no problems (yet). I will say that after I did the bypass on the 2500, the "security" light is always on.

Pretty sure my basic explanation of the system and its downfalls should make this easy to figure out. The Suburban is likely experiencing increasing resistance in other connections in that circuit, causing the reading to drift out of what the TDM is expecting, regardless of your resistor fix.

There's a range of resistance values that are acceptable once the TDM is "learned" that is the correct reading. You can re-learn to different values within that range, and the truck will start as long as the reading stays close to that. Then a little more connector oxidation or solder joint issues along the line and there goes your re-learn and you're back to square one.

This. Is. Why. We. Are. All. Saying. Tune. it. Out. Of. The. PCM.

Richard

 

[JimRMac]

Yes, got the message and not arguing it. Just trying to get a better understanding of how it all works; resistor bypass, PCM reprogramming, etc. The good thing is, the suburban is not my daily driver, use it to pull boats and my hunting vehicle in the fall. And, luckily, it died in my driveway, not on the boat ramp or in the deer woods so I definitely want to fix it permanently.

 

[HotWheelsBurban]

Fortunately my Burb only dumped us once on the road. At work a couple towns out from Houston, 20 miles even from my shop building, and go to leave and it won't start. Called a tow truck, he couldn't get there until 2 hours later (bad wreck on the freeway between him and me, so loads of traffic). When he gets there, just before hooking it up, I decided to see if it would start. Lil bastid fired right up!
That "hot no start" was fixed by replacing the battery cables(corrosion where I couldn't see it) cleaning the connections and starter, and tightening the ignition terminal on the solenoid (the little one, I think a purple wire goes to it). No more problems with it, starter lasted another 2 years or so.

 

[someotherguy]

If you get tired of waiting for the eternal SECURITY lamp to burn out, you can always just remove the bulb from the cluster.

Richard

 

[HotWheelsBurban]

Every other time, was at wherever we were living then. One time, before the Passlock went nuts, it was the Crank fuse. I've seen that on another Burb too; replace and all is well.
The last time was last fall, was the fuel pump finally saying "F y'all, I'm done" in the driveway after being driven a bunch that weekend. Of course the fuel pump always croaks when you just filled it up, so you have to find some place to put 42 gallons of gas.....but that's another story.

 

[JimRMac]

Ok, it was the passlock acting up. Did a reset and it fired up after the first cycle. I have a parasitic battery drain issue (which led to the whole no-start problem to begin with) that I'll try and solve first, then see about replacing the resistor and hopefully that'll keep me running long enough until I can get the PCM re-programmed. Thanks for everyone's input!

 

[jgas]

Ok, it was the passlock acting up. Did a reset and it fired up after the first cycle. I have a parasitic battery drain issue (which led to the whole no-start problem to begin with) that I'll try and solve first, then see about replacing the resistor and hopefully that'll keep me running long enough until I can get the PCM re-programmed. Thanks for everyone's input!

1998 chevy 2500 here. 140.000 original miles. Good condition. I know, i bought a peach. For once!

I am sitting on the roadside with the start/die problem. I just did the key reset, turn on for 30. Off, on 30, off, on 30. Started on the second try. I'm afraid to shut it off since I'm 50 miles from home.

Background. We just got past a rare 10 day snow ind ice freeze. Now we have potholes so bad they are closing bridges. I mean holes all the way through some like hit with a bomb. I have hit a few, had to replace a tire last week. After hitting a big one my security warning light came on, but the truck ran fine until I shut it off, then the start/die problem. It's been idling fine as I wrote this. The security light went off after driving a few miles.

Questions. Likely to restart? What do I replace? Is the reflash the best/only way? If I shut off and the problem returns, should I just do it again? How long does this key reset usually work? I need to wait until next payday. March, to spend the 300 to get a reflash, and drive it until then if possible.

I know I'm asking hypotheticals. But sitting roadside that's what you do. Yall have already got me running again for now! Thanks!