p1500 CEL Need help!!

[GSTPerformance]

Hi all, so i got this code today on my 97 GS-T, p1500 Alternator FR Terminal Circuit is what pops up. I did some research and it has something to do with either my alternator or ECU has gone bad. I would like to know how I can test to see if I have a bad ECU.

[dogwhistle]

If the alternator is a Saturn alternator, this is a common code you can generally ignore. As for the ECU, I'll do some digging on what you can do for testing ASAP

[polishmafia]

How many volts is the alternator putting out? Have you tested that?

[GSTPerformance]

I haven't tested anything yet since im not sure how to do it. My turbo timer has a volt meter and it seems to be around 12.5v also my pioneer stereo has a volt meter and that reads 12v-13v. The alternator is fairly new, i replaced it 4 months ago from Autozone.

[dsmghost]

Check voltage on the FR circuit at the alternator. Without an electrical load it should be 1.8-2.4 volts. Then check the voltage to the alternator with connector unplugged it should have 5 volts coming from the PCM. If those check good replace your alternator.