1999 Tahoe security problem

[ranger2751]

Hello! I swapped the motor in my Tahoe, had the PCM flashed and now the "security" system will not let the engine start? Any suggestions to get around this?

 

[exp500]

Reprogam your keys to pcm via instructions from whomever flashed it, Or use a 2 way scanner such as Tech 2.

 

[Eman85]

Keys are not programmed on these vehicles, there is a sensor in the column but it doesn't sense the key only the turning of it. If you had your PCM reprogrammed a good programmer would have suggested removing the security system from it.
How do you know it's the security system preventing starting? Turn the key to the on position, does the security light come on? If you leave the key on does the security light turn off? When attempting to start does the engine start and die as soon as you release the key? That is how the security system acts when it is activated. Do the google thing about resetting the security system as I can't remember the amount of time. All you have to do to reset is turn the key on and go have a cup of coffee, it will reset itself.