After sitting a full day without being started, upon start-up, my check engine light came on as I shifted from park into drive, and the drivetrain made a "clunk", and felt funny as I started to drive forward out of the garage.
I checked the codes with my Predator, and the code P0700, TCM Malfunction came up. It took several attempts to get it to clear. This happened once previously, right after unplugging one of the harnesses under the dash to wire a diode in to my headlight circuit.
I run the Predator on the 40 HP tune, and I did tow the last time I drove the truck, but everything seemed normal. The trailer was a small 6x12 cargo trailer with two dirt bikes in it, not much weight. Cool temps outside, no steep or long grades. I did run it through the automatic car wash the day before, but that shouldn't be any worse than driving in the rain I wouldn't think.
I did have the Predator on the 65 HP tune for a couple of weeks, but a couple days prior to this last tow I turned it back to the 40 HP tune. If the tranny sensed some slip, causing the code, would it wait till the next time I started it to show up?
Any ideas????

P0700 means you have codes in the TCM, which the Predator cannot clear. You will need to get the TCM codes read/addressed.

Well, it has done it twice now on the stock tune, but then it now went for two long days without setting a code. Nevertheless, it's got an appointment with the dealership for Tuesday. I'll post the results when I get it back.

Got the truck back today, after only two days in the shop. It had a defective valve body. They replaced it under warranty, and gave me a free rental truck while they had mine. The truck has 4500 miles on it now.