I was pulling my boat today (about 10K Lbs) and about 30 miles into the trip and right before a huge bride my truck went into limp mode. 2000 RPMs max. No choice but to limp over the bridge and get to where I needed to go. Dropped the boat off and even unloaded wouldn't come out of limp mode. Once I disconnected the batteries it cleared and all is well. What causes this? Fuel issues? Allison laying down on me?