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2003 Monte Carlo Passlock issue

  #1  
Old 07-09-2019, 04:40 PM
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Default 2003 Monte Carlo Passlock issue

I have a 2003 Chevy Monte Carlo 3.4 LS. The security light starting coming on and starting locking out the starter. I have to relearn the key almost every time I try to start. I tried a new key cylinder, but the issue remained. I tried wiring in a 2.2K resistor to it, but it remains. Does anyone know the fix? Is there any wiring diagrams? I would like to know what enables the starter so I can rig it to always have the voltage to enable it to start. I have to leave the car running wherever I go so I donít get stuck for 30 minutes. Thanks for any help you can give.
 
  #2  
Old 07-09-2019, 04:55 PM
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First, wiring in the 2.2k resistor, do you know if that is the proper resistance for your car? They vary, so if it is not correct, you only add to the problem.
Second, I have heard of a story like yours. It turned out the teeth on the key were worn out enough that they could still turn the lock cylinder, but not activate the passlock chip. Solution in that one odd ball case, have the dealer cut a new key based on the VIN number.

Passlock consists of the chip in the lock cylinder, the BCM and PCM. If I recall correctly, if all is good with the security, the PCM will then ground out a relay, which energizes the starter (this is from memory, so it would need validated).
 
  #3  
Old 07-09-2019, 06:24 PM
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Originally Posted by The_Maniac View Post
Passlock consists of the chip in the lock cylinder, the BCM and PCM. If I recall correctly, if all is good with the security, the PCM will then ground out a relay, which energizes the starter (this is from memory, so it would need validated).
Yes that is how it is on my 2002 Monte Carlo. Pcm sends ground to starter relay.
 
  #4  
Old 07-13-2019, 11:03 AM
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Default Bypass the pcm

Is it possible to rewire the ignition switch to directly energize the starter? Or is there a way to cut the wire that tells the pcm not to start?
 
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Old 07-13-2019, 05:28 PM
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No you can't just bypass the bcm and start the car. If you try to bypass the computer and energize the starter the computer will shut off the car as soon as it starts . Wish there was a better answer. Good luck.
 
  #6  
Old 07-14-2019, 08:22 PM
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Default Disable Passlock Completely

Is there anyway to disable passlock completely. I need my car to start when I want it to. It keeps going to lockout. Can I cut the lockout wire? Which wire locks the car for passlock? I am not taking it to a dealer. Iím not a millionaire. I will Hotwire the starter enable relay and fuel enable relay, whatever I have to do. I just need to know which wires from the 3 bcm connectors I need. Does someone have a pinout diagram or something that is readable.
 
  #7  
Old 07-14-2019, 09:30 PM
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https://montecarloforum.com/forum/mo...e-learn-60964/ The Maniac has a reply on this list post . He shares a link with the information that you need. Good luck
 
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Old 07-15-2019, 11:48 AM
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Put all the PassLock wiring back to factory, use the attached re-learn process (this is straight from the GM shop book). Some important notes, ensure that your NEVER remove the key during the process. Also, watch the security message on the dash, you cannot proceed until that security notice stops displaying (which takes around 10 minutes).
I would do this before cutting up anything else. Honestly, this security system in these cars is not that complex (but can be a pain if it does not work). It can also be possible the passlock chip in the lock cylinder is bad (rare, but it has happened). Hopefully the problem is not more involved (like chasing a failed/damaged wire).

I believe I might know the tricks to disable passlock in the PCM with my tuning device (but it has never been tested and I don't have a true way to test it).
Only other bypass I know of is using a bypass module required for an aftermarket remote start. I'm not sure how well that works without the remote start system.
 
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