1999 C1500 GMC Suburban 5.7 fuel issue

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Pro439

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Wester’s Garage can take it out and whatever else you might want to turn off. Also that hose is not a vacuum leak it just lets crankcase gases back into the inlet of the throttle body with it off it would affect the map sensor as you wouldn’t be moving as much air past that sensor but it definitely is not a vacuum leak in that sense and at idle I don’t know that the map sensor would notice it
 

Mister1500

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Okay, so I found a possible solution that seems simple enough. Basically eliminating the need for any programming or kit purchase. I’ll let you know if it works. If it does I’ll share for anyone else with the security nightmare. I’ll try to do it in the next day or so
 

Pro439

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Thank you. I’m not a pro on the computer stuff for sure but I wouldn’t think at an idle it would be that big of a deal. But I also have never monitored it on a data log either to be absolute
 

Mister1500

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Okay, so here goes……… ITS ALIVE!!!!!!!
My 1999 Suburban is running again and it cost absolutely nothing to fix other than about 40 min of time!
Since I don’t want to break any posting rules I will not at a link. However if you search 98-00 GM theft system erase on YouTube you will find a video approx 9 min in length by Andy Kendeigh on how to permanently erase the theft security system. It works for intermittent system and total system failure.

I hope the forum puts this somewhere it can be referred to for others with this same fault!
 

df2x4

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Okay, so here goes……… ITS ALIVE!!!!!!!
My 1999 Suburban is running again and it cost absolutely nothing to fix other than about 40 min of time!
Since I don’t want to break any posting rules I will not at a link. However if you search 98-00 GM theft system erase on YouTube you will find a video approx 9 min in length by Andy Kendeigh on how to permanently erase the theft security system. It works for intermittent system and total system failure.

I hope the forum puts this somewhere it can be referred to for others with this same fault!

Be aware, I'm 99% sure that this method will leave you stranded again if you ever have to disconnect the battery for any length of time. It's basically a variation of a temporary bypass for remote starts and the like that was described in the GM Upfitter's Guide, which was designed to be used with a toggle switch and a functional PassLock module. If the PCM loses power, it will start looking for a PassLock signal again. This has been discussed a few times here before, but unfortunately the PDF links describing the procedure all seem dead.

https://www.gmt400.com/threads/interesting-passlock-workaround.22463/

https://www.gmt400.com/threads/how-to-do-away-with-factory-passlock-security-system.16939/

As JOHNGAAA1 mentioned on page two, the only way to permanently disable the PassLock system is to turn it off in the PCM tune. Which is extremely easy to do yourself if you have access to tuning software (EFILive, HPTuners, JET DST, etc), but if not there are several mail order tuners who can do it. Black Bear Performance, Nelson Performance, Wester's Garage, PCM4Less to name a few.
 

Mister1500

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Thanks for that info. I have disconnected battery and will be testing this in a day or so when I can get back to it and hook up battery and see what happens
 

Mister1500

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So your are correct. The security system bypass stops working anytime power has been disconnected. So off to have the PCM flashed and VATS deleted. Since I am at it, are there any recommendations for upgrades that will help the Burb, but not hurt reliability? I plan to keep it stock since it is going to be my daily. Any suggestions are welcomed.

Thanks!
 
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