Toyota corolla 2003

i have a 2003 toyota corolla ce. 2 weeks ago, the engine suddenly died (while the car was moving), but it would restart again when i started the engine. Happened twice in that week. Last week, the battery was completely died, and i replace it with a new one. Just happen today, about a week after i replace the battery, the car won’t start at all! Not even cranking. I check the battery with volt meter and showed 12 something volts. When i put the key in the ignition cylinder, i didn’t hear the door chime; when i turned the key to “ign” position, all indicator lights were on, but dimmed. Stereo, A/C, and headlight worked as normal. When i turned the key to “start” position, the engine didn’t start; and when i turned the key to “off” position, the e-break light, air bag light, and the oil light were on. I had to disconnect the battery to clear the indicator lights. Any suggestions what would it be?

I certainly not saying it is the problem, but you should be able to remove and clean all ends of each battery cable.

I think you have a bad electrical connection somewhere. Start with the battery cables. Make sure the connections are clean and tight at BOTH ends of each cable. I suggest having the charging system checked. Most parts stores will do this free.
It’s also possible that the ignition switch is the problem, but that usually only happens on much older cars.

For sure i have electrical problem, but what or where is it? I checked and cleaned the battery terminal, they are ok. And i checked the ignition switch, it is ok too. A friend of mine said, it might be the BCM. Does anybody know how to check the BCM without the scanner? and where is it located (since my friend does not know where it is located)?
Thanks before.

Dayak Wong