So... we're back to functioning with no codes.
We'll see what it does the next few days.
Been an odd string of issues.
Last week the significant other gets limp mode coming home from work, says it started very soon after hitting a pretty good pothole (Oklahoma City has some serious potholes).
It would drive a few miles before going into limp mode, and even made it the full ten miles home the last day she drove it to work.
I made sure the pan wasn't busted (again, she did that on a pothole once before, yay Oklahoma), checked the fluid and replaced the valve block and in/out sensors with an
amazon unit. At that point it was in limp mode before it was even out of the neighborhood, less than a quarter mile at 12mph.
Worse than it was.
While waiting for my scanner to show up, I pulled the trans harness and stripped it and did a physical exam and a pin to pin continuity test while yanking around
on it and found no issues. Reinstalled, no change.
Got the scanner in, had a communication error.
Started doing the astg tests and found a bad voltage drop on one of the ground wires to the TCM.
Went to bed after doing some more reading.
Next morning, bad ground is gone, scanner connects, code 31.
Cleared code, drove fine.
Still does.
I pulled all the connectors and contact cleaner'd and eyeballed them close and still see nothing wrong.
I cleaned the ground on the passenger inner fender, voltage drop was fine everywhere.
Sooo, I'm a little puzzled.
I think maybe there was a bad ground that acted up when she ran over whatever asphalt crater there was, and I fixed it, somehow.
Possibly temporarily.
I'm bothered that I don't know where it was exactly and thus far I can't replicate it, I don't have a correct factory wiring diagram showing ground points
and all, I need to acquire that.
I'm not positive how that code equates to a bad ground either, but bad grounds can do weird things.
It could still be the trans, or the TCM, or a ground that will go south again.
Other than drive it and see I don't know what else to do.
I do have a spare (claimed) known good TCM, and a reman trans if need be.
But I'd just as soon not swap trans right now if I don't have to.
The clutch fill rate numbers looked good on the scanner so it's not obviously shot.