I have a 2000Cadillac Deville,it has 123,000 miles. on 2000 Cadillac DeVille

the check engine light is on among other things.The battery not charging light comes on and go back out,but comes on again.I took it to Firestone,they couldn't find anything.The alternator is working fine,the battery is working fine but light comes on and off.The check engine coolant light comes on but all of the fluids are full and I have the oil and everything changed at 3000 miles.Could this be the BCM unit going out? I have read some thing off internet that states it could be the BCM in car.Can someone please help me with this question??????

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what were the codes you had when you had it scanned?