Trouble code 18010 Power supply (B+) Terminal 30 - Low voltage

I recently noticed the check engine light was lit in my car. So I bought an engine scanner to see what the problem was (I thought it was the MAF). But the scanner read: 18010.
In the the manual, that came with engine scanner ( I don't have my car's owner manual), the definition given for this code was: Power supply (B+) Terminal 30 - Low voltage. But that doesn't tell me much. Could anybody out there, please let me know what this means. After scanning the engine, I erased/reset the problem code and the check engine light is now off, even after a good ride.
Also, my car is a 99 A4 2.8
Thanks any thoughts would be great!!
I'd like to fix this myself if possible.
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The code 18010 has the following possible causes :
a) Weak battery b) Alternator fault c) Cables disconnected from battery.
Have you disconnected the battery recently ? I'd personally ignore the problem unless the 'Check engine light' reappears. Then check the cables to the battery, the battery itself and then the alternator.
Richard
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Yes I did, recently unplug my battery and I remember it being a little loose when I replugged it. But lazy me, I didn't re-tighten the wire until I saw the check engine light come on. ( I must have hit a bump and the wire must have moved slightly). I had a hunch that it could of been that. Well thanks alot. Richard Goulding wrote:

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No problem. I hope it's solved.
Richard
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