Security light on constant and battery drain

212,020 MILES • 3.4L
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VINCE SYLTE
  • MEMBER
  • 1 POST
Hi the security light on my car stays on continuously even when the car is running and the battery will drain down over night if I don't disconnect it
The vehicle had this problem when I acquired it recently signed I had gotten a battery fully charged and it did all kinds of weird stuff from the gauges moving erratically and a clicking by the glove box which I found was coming from the bcm
So I replaced the bcm and Did the security relearn sequence of of this site and the car started but the light still stayed on constant from there on it started every time for about two weeks then one day the battery was completely dead si now I'm kind of wondering where to start looking? Possibly the ignition switch, a bad ground maybe I'm kind of at a stand still any thoughts or info would be greatly appreciated
Thank you very much really love your site has given me much information to do with all my vehicle s in one way or another.
Oct 19, 2019 at 10:52 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,548 POSTS
It sounds like the CPM is not going into sleep mode. You could have bad grounds causing it I would do a CAN scan to see what comes up you can get a CAN scanner from Amazon for about $50.00 and is the future of car repair. Here is video of the job being done:

https://youtu.be/InIlnsjOVFA

Also here are the PCM wiring diagrams and a guide to help check power and grounds. You can also see how the system works.

https://www.2carpros.com/articles/how-to-check-wiring

and

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

Check out the diagrams (below). Please let us know what happens.

Oct 26, 2019 at 5:46 AM
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