Without warning, I started my car up today and drove it and the battery guage would go down to 0 while driving, and the code would display, "Service vehicle soon, Security". Also, due to this problem, my AC's not working! My radio just says, "Locked" on it and I can't even turn that on. The car never surged like it was the alternator and the battery is only 2 years old. Full power throughout the whole tac too. I have no idea what this could be. Anyone else?

Since it's saying "Security" and "Locked" on the radio display, could this be an electrical problem with the original security system? I've got a new security system, which is disconnected and has been for 2 years... Don't think that should be a problem.

 

Okay, let me get this right:
You have a Service Engine Soon light
You also have a Security light
Your air doesn't work, and you have displayed on your Radio "LOC", correct?
Your theftlock is active on your radio and that tells me that you have had a power loss at some point. I would check the amperage on your battery and your alternator at an auto zone or place like that. They can test both in your vehicle. What year is your monte and what motor do you have? Also, welcome to the forum!

 

Body Control Module was the correct answer for those that saw the problem, just didn't post it. LOL I called my othermechanic who said that it's best just to have the dealership do the work. I guess the part is around 250, then it has to be set by a $7,000 machine. He said most mechanics have cars sent to get the work done since they don't own one of those $7K machines. It's just as easy to get the body control module replaced at the dealership so that's what I'm doing........... I've now spent almost $1K in the last two weeks on my car, money that could have gone toward the Charger R/T I want..........

 

Lesson learned: Instead of throwing parts in your car that may or may not work, go to the dealership, spend the $85 to get it diagnosed with Tech II and problem solved! ) I'm glad that you found out that it was the BCM.

 

Does the BCM ever reset itself? This happened to my car and the dealer told me to let it run for 30 minutes and it may reset itself. I just replaced the battery in it. It is a 2002 Monte Carlo SS. The autolocks were continuing trying to lock and unlock the doors as well as the high beam light flashing....any suggestions?