Check Engine Light, Code P1794

[90blue]

I am getting a check engine light on the '97 I recently acquired, suddenly.
P1794 Powertrain Control Module Battery Direct Power Circuit.
I can not find much on this code other than it is a lack of electrical power, or how to correct it.
Hard to believe it could be an alternator but why not.

I have limited experience with OBDII and need assistance with this please.
Info:
1997 5spd 65,000 miles
New battery
car has an alarm, a Clifford now disabled
starts and runs fine

Is there a power control module ?
Where is it located ?

Does anyone have experience with this code ?
Thanks in advance

[BoBo]

It might be due to a bad ground or some kind of faulty wiring like an electrical problem, last but not least a bad ECU. The easiest way to start is to swap out the ECU for another 96/97 ECU. If that fixes the problem, then you know it's the ECU. If you have an ECU ready for the swap, clear the code first before you swap out the ECU, and if the code doesn't come back after 75 miles you're good.

In addition, check the fuse box if everything is OK. If you don't have a blown fuse or one that's not seated, it's more likely an ECU issue. A voltage tester will indicate this.

Ive dealt with this issue with other trucks & cars, but it should be the same with a Miata. This issue will keep you from passing smog. Good luck!

[90blue]

Thanks I'll check the grounds and ECU connections tomorrow.
Wish I did have another ECU laying around.