Prodigy Error Codes - help!

[Camping Coxes]

We have an '84 Suburban Diesel pulling a '98 Coleman Sunridge.  We have the Tekonsha Prodigy brake controller.  We've towed about four times with no problems.  However, on our last outing, just as we got on the freeway, we felt the trailer braking hard when we weren't applying our brakes.  The error code was reading both SH (short) or another one I can't remember offhand that says we lost our ground/the brake wiring is disconnected/the trailer is not attached.  We continued on our trip and it happened a few more times.  It wasn't enough to send our Suburban off course, but it was startling and we were concerned about damage to our brakes.  It seemed to happen when we were on a bumpy road or going over lane markers, both of which would make the trailer bounce a little.  When we arrived at the CG, DH checked for frayed or loose wiring but saw no problem.

We took it in for repair and they had no problems and of course couldn't duplicate the problem.  They checked all wiring and said it was fine.  As I brought it home and parked it, it gave me and SH code, which means that it's detecting a short at idle conditions.  This is new, since it never did it at idle before.  We're taking it back Saturday for them to try again.

Does anyone have any ideas on what could be wrong?  At this point I want them to unhook the Prodigy and just try a whole new unit.  No changes to any systems have been done between installation and this last trip to cause the wiring to have been changed, so I'm wondering if the unit isn't defective.

Thanks in advance for your help.

[MtnCamper]

Sounds like a bad connection between the truck and trailer. I would clean the plu on the truck really well, then get a tube of dielectric grease and fill the holes in the plug in, then work it in and out a few times. You may never have the problem come up again.

[Camping Coxes]

Update:  We took the truck and trailer back to Camping World and they said they'd run tests on the controller itself, on the trailer brakes using their tow vehicle, on the truck brakes using their trailer, etc.  Turns out, we got a bad Prodigy unit.  Thank goodness for warranties!  So they installed a new Prodigy, and DH said it worked like a charm on the way home.  

We always joke that if "it" is going to happen, "it" will happen to us.  So we should have known we'd be the ones to get that one bad unit out of all the units on the shelves the day we had ours installed.