error codes

I forgot to mention that this a 2015 Ram 2500 HD with 6.4 gas engine. So last week these caught my eyes while looking at the dash: The engine wouldn't rev above 2,500 RPM, trans wouldn't go higher the 4th on 6 speed, cruise control wouldn't work, speed toped out at just over 55...

Hi, I own an 80 an 73. Therefore this is not my primary forum. However, I am trying to help a friend with a 95 of December 1999, with an 1KZ-TE engine. Concretely, he has an issue with the airbag light, and I know from my 80 that it is possible to check error codes using a jumper wire between...