Security system issues

Tiny
MR51575
  • MEMBER
  • 1999 CHEVROLET SILVERADO
  • V8
  • 4WD
  • 13,600 MILES
I just bought a 99 Chevy Z71 two days ago. On my way home from work, the Security light came on. When I got home, I turned the truck off and restarted it. Everything seemed fine. Later I get back into the truck to go to work, and the light starts flashing. When I try to start the truck, it fires, but then shuts off like it's not getting any fuel. Had to leave truck home. When I get home, the battery is dead. Got it in charger now, but ho do I get te thing to start so I can get it fixed?
Monday, January 10th, 2011 AT 12:11 PM

39 Replies

Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
You have an issue with the Passlock immobilizer. It requires a Tech2 scan tool to be able to diagnose these but one of the more common problems is the sensor in the ignition switch messing up. I'm giving you the relearn procedure that may or may not work. If it doesn't or if it happens frequently, you will have to get it diagnosed properly.

This guide can help

https://www.2carpros.com/articles/how-to-reset-a-security-system

PASSLOCK 10 MINUTE RELEARN

AUTO LEARN
Time required, approximately 10 minutes:

1. Insure that the battery is fully charged.
2. Use the scan tool in order to clear the DTCs.
3. Turn the ignition switch from the OFF position to the CRANK position attempting to start the vehicle. The vehicle will start and then stall.
4. Leave the ignition switch in the ON position while observing the security indicator.
5. When the security indicator turns off, which can take up to 10 minutes, turn the ignition switch off. Wait 10 seconds.
6. The BCM and the PCM will learn the new code on the next start attempt.

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Monday, January 10th, 2011 AT 12:58 PM
Tiny
GOTECHSLACK
  • MEMBER
  • 7 POSTS
  • 1999 CHEVROLET SILVERADO
  • V8
  • 2WD
  • AUTOMATIC
  • 222,000 MILES
Hello. I have the stated truck. The "Security" message came on while driving the other day. When I turned off the truck and started it, the message went off. This happens periodically, but not all the time. It can go days without coming on. Any ideas? Thanks.
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Monday, November 18th, 2019 AT 11:34 AM (Merged)
Tiny
RHALL77
  • MECHANIC
  • 3,361 POSTS
You may have to stop somewhere and have it scanned for trouble codes. When you do, get back to me with the codes and ill see what I can do to help
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Monday, November 18th, 2019 AT 11:34 AM (Merged)
Tiny
GOTECHSLACK
  • MEMBER
  • 7 POSTS
Thanks. Will do.
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Monday, November 18th, 2019 AT 11:34 AM (Merged)
Tiny
JAF1978
  • MEMBER
  • 6 POSTS
  • 1999 CHEVROLET SILVERADO
  • 5.3L
  • V8
  • 4WD
  • AUTOMATIC
  • 204,000 MILES
So I need some help. When I bought it, it did not come with the key fob. Got one online and would not program. Been dealing with this for a year now. Went out today and got a new key-less entry module with two fobs. Still will not program! I'm doing the usual hold down unlock on drivers door, turn key on off on off and it goes into program mode. That's where it ends. I also checked the fuse and it's good. Am I missing something? Help!
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Hi,

Just so I am clear, you are able to enter the programming mode and it cycles the locks only once to indicate this or does it cycle the locks more than once? If only once, when you hold down the lock and unlock on the fob for 15 seconds, it doesn't cycle the locks again?

If this is the case, we need to scan the BCM to see if there are codes. More than likely you have something in the BCM that is preventing it from completing the process and if so, there should a code to give us a clue. Let me know what that is if there are codes and we can go from there.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
JAF1978
  • MEMBER
  • 6 POSTS
Yes, when entering the programming mode the locks cycle only once. After it cycles, I hold the lock and unlock on the fob for at least 15 seconds to 1 minute and nothing happens. One thing I did notice is when I start driving, my seat belt light flashes for about a min then goes out even though I have my seat belt on. I'm not sure if that has anything to do with it.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Okay. If it doesn't enter programming mode then the BCM is most likely the issue. When it does enter but fob's don't respond the the receiver module is usually the issue. Basically you are turning the key and the BCM sees that you are doing this and enters the mode. Then you press the FOB buttons and the receiver module is responsible for receiving the signal and sending it to the BCM. It never picks it up so more than likely it is the issue.

It is located in the center of the dash. Pictures attached.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
JAF1978
  • MEMBER
  • 6 POSTS
I just replaced the receiver module and it still will not program.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
JOESRIDE
  • MEMBER
  • 1 POST
  • 1999 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 103,500 MILES
For the past 4 years I have been dealing with the factory alarm for which I don' t have a keyless entry transmitter. I often have the problem where the engine fires up then automatically triggers the kill switch to which I have to wait anywhere from 15-45 minuetes before the truck starts. I have contacted the dealer and there answer to the problem is.". Reprogram the alarm system for a fee of about $500 -700 dollars". With this economy I just don' t have the funds to do it right now. Is there anything I can do to disconnect or bypass this problem. Please help.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
DAVID59
  • MEMBER
  • 1 POST
Hey joe I see you have the same problem as mine, only I have been trying to solve this alarm issue thing for over 4 years now, with no direct answers as of today, if I run across a good solution to our problem I will be sure to post the answer so you can get on with your life. Really now i'm looking at purchasing a new alarm from J. C. Whitney called a Valiant, the item number is 1JA478507, however I too don't have a lot of free cash, so i'm looking for this product at a better price that what J.C. Whitney wants? More if and when I find something.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Unfortunately, I suspect the only thing left is the BCM.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
JAF1978
  • MEMBER
  • 6 POSTS
Okay. Can I get a BCM from a junk car (same year and model vehicle as mine) and put it in my truck?
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Yes. I would just pull yours out or at least see if there is a part number on it and get the same one. Just same model and year will not be enough to be sure they are equipped the same.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
JAF1978
  • MEMBER
  • 6 POSTS
Awesome. Thank you so much for your help! If I have any more questions I'll let you know.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Sounds great. Thanks
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
HOZER
  • MEMBER
  • 1 POST
  • 1999 CHEVROLET SILVERADO
Electrical problem
1999 Chevy Silverado 6 cyl Two Wheel Drive Automatic

this truck was stolen and the sterring wheel had to be replaced
also I replaced the fuel pump and fuel filter
I also put a new battery into this truck
it starts and stops right away and if you try to hard to keep turning it over to start I wont fire again untill you let it recycle the computer
the truck was towed
my question is how do I get this thing to start and stay running
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
JASONRAY
  • MECHANIC
  • 213 POSTS
Try to start the engine. Release the key back to the "RUN" position and let it sit for 10 minutes. Turn the key OFF. Turn it back on to RUN and let it sit again. Do this 3 times. Then try to start it. This should reset the security system. Just to be on the safe side, though call your local dealer and double check me on the times. I've dealt with several of these and I may get the procedures confused. I don't want to give you incorrect info so double check me.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
JAMESPM
  • MEMBER
  • 2 POSTS
  • 1999 CHEVROLET SILVERADO
  • 5.7L
  • V8
  • 4WD
  • AUTOMATIC
  • 168,000 MILES
Security keeps coming on & the truck will not start. We have tried to reset many times. The security light will go off; but as soon as we try to start the truck; the light will come back on & the truck will not start. We have replaced the security module & there is not a chip in the key. Is there something else that would cause this issue?
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Friday, July 24th, 2020 AT 11:38 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,055 POSTS
First, are you sure of the engine size? I'm not showing a 5.7L for this vehicle.

Also, everything I show says the key should be chip in the key. There is a hall effect sensor that determines if the key is correct when you turn it.

Listen, I need you to have the computer scanned to see if there are trouble codes. I have system checks, but I have no idea where to look for your type of problem.
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Friday, July 24th, 2020 AT 11:38 AM (Merged)

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