A friend borrowed the CRD to tow a smallish trailer. When I started the Jeep, it immediately had the hazards and parking brake light stuck on and CEL/MIL flash on shortly thereafter.

I happen to carry a small tool kit with a code reader under the passenger seat, so I immediately checked the codes. After running through a couple searches on my phone I found the procedure to test: http://www.jeepforum.com/forum/f19/help ... se-899133/

Basically: (a) check the fuse, (b) pull the relay and check with a test light with vehicle on 'on' but not running, (c) try swapping the relays. The defective part, for me, was the transmission control relay. I swapped it for the AC clutch relay (and reset the code) and everything worked perfectly - except my AC of course! It's always nice to be able to diagnose and temporarily fix a problem without having to spend any money.

If you don't have a tool kit, you can check the codes with the on-off odometer method and pull the relays by hand, so overall this may be a CEL you can solve without a single tool!

From the parts fiche the relay is part number 04671168 - just over $10 online. Of course this won't help every time, but just thought I'd throw in my experience for the benefit of anyone searching ye 'ol interweb.

PS, as an aside - I haven't really posted much here and I anticipate selling the CRD shortly to replace it with a 2014 EcoDiesel Ram 1500. But many thanks are owed. I honestly would have driven the Jeep off a cliff had it not been for this forum! It's saved me thousands of dollars and hours of frustration (though admittedly, in an effort to save thousands of dollars, I've also subjected myself to many hours of frustration - all worth it in the end I suppose!). It's truly remarkable how effective these forums are for maintaining and troubleshooting. I only wish I had more to contribute. Cheers and Namaste!