Truck won't start security light always on!!!!

Asked by Jan 01, 2017 at 09:58 PM

Question type: Maintenance & Repair

I have a 2000 Chevrolet C2500 and my
security light is always on. It will start but
turn off after a few seconds. The dealership
said it's the theft control module. So I
bought this part from newrockies that is
supposed to fix this problem but that did not
work and my brother pulled the TCM out and
took it out of the box it's inside and it looks
fine. We have been messing with it for 3
days and get it to start.

2 Answers


Simply replacing the anti-theft module is only half the repair. Your keys have to be programmed to the anti-theft module before you can start the truck. This must be done with a scan tool. Either at the dealer (preferred) or by a competent lock smith. HTH. -Jim


Did you,try running the disarm procedure in the owners manual first? But it maybe too,late now as you have put in another module, but you can try putting the old one back in and run the protocol, if it don't work the you still have the new module and tow it to a dealer for the reprogramming of the new module.

Your Answer:

Maintenance & Repair Experts

  • #1
    Tom Demyan
  • #2
  • #3
View All

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.