Passlock question

Tiny
SPECTOR37
  • MEMBER
  • 2004 CHEVROLET SILVERADO
  • 121,768 MILES
The battery in my 2004 Chevy Silverado died yesterday and before that it would start and run fine. Now the problem is I charged the battery and tried to start it it will turn over like normal and start for about a second and die. Now the question I have is does the passlock system need to relearn the codes again before it will start?And will the battery going dead cause the problem?
Thanks
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Friday, January 27th, 2012 AT 6:46 PM

15 Replies

Tiny
WRENCHTECH
  • EXPERT
If you are getting any kind of security system indicator, here is the relearn procedure.

Disconnect the battery and hold the cables together for about 30 seconds then reconnect the cables before performing the procedure.Read it carefully if done incorrectly it won't work.If it helps let me know.
Turn ON the ignition, with the engine OFF.

Attempt to start the engine, then release the key to ON (vehicle will not start).
Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
Turn OFF the ignition, and wait 5 seconds.
Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the Passlock Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK).
Important

The vehicle learns the Passlock Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
Start the engine (the vehicle has now learned the Passlock Sensor Data Code and/or password).

With a scan tool, clear any DTCs if needed (history DTCs will self clear after 100 ignition cycles).

This guide can help as well

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

Please let us know if you need anything else to get the problem fixed.
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Saturday, January 28th, 2012 AT 3:13 AM
Tiny
HALL058505
  • MEMBER
  • 2004 CHEVROLET SILVERADO
2004 Chevy Silverado

the alarm went off and they got it to quit but now it wont start what do I do now?
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Monday, December 10th, 2018 AT 8:10 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
Is the security light staying on?

Let me know.
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Monday, December 10th, 2018 AT 8:10 PM (Merged)
Tiny
MMIKE1234
  • MEMBER
  • 2002 CHEVROLET SILVERADO
  • 100,000 MILES
My used 2002 Silverado has the anti theft feature and I don't know the unlock codes. After the battery was changed my radio no longer works. How can I obtain the security unlock code? Or do I have to take to dealer?
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Monday, December 10th, 2018 AT 8:10 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
You will need to see a dealer to get that bypassed.
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Monday, December 10th, 2018 AT 8:10 PM (Merged)
Tiny
MANNING75
  • MEMBER
  • 2001 CHEVROLET SILVERADO
  • 306,000 MILES
Security and battery flashes on the message board. Everything electrical seems to work, but the starter will not make a sound, and I can hear relays engage when I turn the ignition to the start position. There is not a problem with the starter.
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Monday, December 10th, 2018 AT 8:10 PM (Merged)
Tiny
SATURNTECH9
  • EXPERT
Have you had the battery tested and made sure the battery cables are clean and tight? The lights take a lot less power then the starter.
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Monday, December 10th, 2018 AT 8:10 PM (Merged)
Tiny
MAXIMILIAM
  • ADMIN
The battery has 12.36vdc, via my meter. I need to know how to reset the security system. I've replaced the key cylinder, and Will not crank.

Manning75
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Monday, December 10th, 2018 AT 8:10 PM (Merged)
Tiny
SATURNTECH9
  • EXPERT
All of the gm security systems from 2000 on don't disable the starter they disable the fuel injectors. You said the starter was inop?You can relearn the pass lock by trying to start it then letting the key go back to the run position till the security light turns off or stops flashing or turns off. Then turn the key off for ten seconds. Then repeat the steps two more times. The ssecurty could be flashing from the doors being open. Ho do you know the starter is good.
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Monday, December 10th, 2018 AT 8:10 PM (Merged)
Tiny
BLUEMOON67
  • MEMBER
  • 2000 CHEVROLET SILVERADO
Electrical problem
2000 Chevy Silverado V8 Two Wheel Drive Automatic

How do you reset or correct a passlock code?
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Monday, December 10th, 2018 AT 8:10 PM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
Are you refering to the fob? If not, refer to the owner's manual for directions about changing the combination on the door. You must, however, know the old pass code to do it.
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Monday, December 10th, 2018 AT 8:10 PM (Merged)
Tiny
NFL4GMAN
  • MEMBER
  • 2002 CHEVROLET SILVERADO
  • V8
  • 2WD
  • AUTOMATIC
  • 22,589 MILES
I've been having this problem for sometime now and I will tell you what I have done. Early in the mornings I go to get in my truck and I push the keyless entry button and get no response, this is a factory installed system (Clifford). If I leave it sit and the wheather warms up the keyless system works. So, I thought maybe the battery was failing so I replaced it and that seemed to do the trick for a couple of weeks. But, now I'm back to square one. Could this be the alternator or the security system. I'm lost with this. Please give me any advice you can. Please ask more questions if you more info. Thanks and God Bless
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Monday, December 10th, 2018 AT 8:11 PM (Merged)
Tiny
MASTERTECHTIM
  • MEMBER
First of all the clifford alarm is not factory installed, but rather it is subletted to a alarm shop. I find usually its shoddy installation of alarm or keyless entry that is the problem.
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Monday, December 10th, 2018 AT 8:11 PM (Merged)
Tiny
WILHARRIS
  • MEMBER
  • 2002 CHEVROLET SILVERADO
  • 6.6L
  • V8
  • 2WD
  • AUTOMATIC
  • 125,500 MILES
Today the security bell began when the engine was turned off. It would not stop until the engine was started again. I checked that all doors were completely closed, the lights were off and there was not unknown body damage.
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Monday, December 10th, 2018 AT 8:11 PM (Merged)
Tiny
HMAC300
  • EXPERT
Could be a switch bad but have it scanned it may be a body module problem.
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Monday, December 10th, 2018 AT 8:11 PM (Merged)

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