p1604

1st Time Post-er, Having some trouble with my 2005 TJ, Automatic 4.0L. 66k miles on her, and has been running great until recently... Driving home one afternoon, cruising at 45 mph (2200RPM), all of sudden RPMs jump to 3000 and the ol' money indicator lamp turns on. She limps home, and that's...

Good day! New to the forum and I have seen a lot of great information posted here. My wife has a 2006 LJ auto with the 42RLE with about 111,000 miles on it. The check engine light came on yesterday after it got started and had a strange idle. got the P1604 code from the self diagnosing we are...

I can't seem to win with my TJ. Just fixed a few issues and now I'm throwing a p1604 code. This is a communication issue apparently with the computer. I just completely removed and cleaned my throttle body and IAC so I'm thinking something during that processes may have caused this problem. The...