Got a check eng, traction control,and battery light on. I checked the battery and was getting 20.4v! I changed the alt and it’s the same thing. Advice anyone?

 

It could be issue with the related components with alternator as bad regulator or bad maf. Try to take a look at this too.

 

Be aware the alternator is controlled by the PCM.

Get the alternator professionally tested.

I've had to replace PCM's before due to charging issues.

 

Thanks for the reply, I haven’t been able to get a definitive answer on that. I can see there is a voltage regulator in the alternator but I have also read it is controlled by the pcm. I can get one for about $200 US but then I have to pay to get my keys reprogrammed also I believe. I don’t mind doing it if it works. I don’t think it’s the alternator, it would be too much of a coincidence that they both put out 20.4v!