Jeep Commander Advice

[Jeep's Jake]

Ok... My brother just bought a 2007 Commander and I will be working on it. Being a 4.0 guy I have no idea what goes on with these things, but I hear they have a lot of nasty design problems. The transmission failing and electrical bugs are my biggest concerns. There are no signs of trans problems yet, but it has 70,000 miles on it, and today it gave him some code (haven't scanned it yet) and it wouldn't let him go over 40 unless he downshifted, and then the problem "cleared" itself. Without driving it, I know nothing more than this.

I know it's not much to go off of, but if anyone else has encountered this problem I would appreciate advice on how to fix it. Ill try and pull the code tomorrow, maybe over lunch hour. Also, If anyone knows of any tricks or preventative maintenance to keep the trans alive, I'm all ears.

As i think about it, Is there a trick (like the ignition on-off trip reset deal) that I can use to pull codes on the vehicle's display screen?

Thanks,
Jake

[SilverXJ]

Sounds like possibly a speed sensor issue. Maybe a solenoid. Definitely pull the code. And you can't pull it with the key on key off trick.