Sorry to bring this thread back from the dead, but I figured my issue didn't warrant an entire new thread.
So my wife and I made the trip down to my father-in-law's house (about 1.5 hours away) to help him with some things around the house on Sunday morning. We took the truck because I had some larger tools to take down with me. The trip down there was fine and no problems as usual. We then went into my mother-in-law's house for lunch before heading back home. As we left her house and before we left the city limits, my "D" light started flashing. This was the first time my truck has ever given me even the slightest hint that something could be wrong even at 139k miles. I immediately pulled off the side of the road and shut the truck down. My wife was freaking out at this point thinking we were going to have to replace the transmission, of course. I checked the tranny fluid, and it was just a smidge below the "low" mark on the stick. I didn't have any fluid with me to add and I was nowhere near a Honda dealership. So, I decided to keep going and keep an eye on it. Started it up and started going again. The "D" light started flashing again about 5-6 miles down the road. At this point I'm worried, but trying not to show it so the wife wouldn't have a melt down. I pulled off the road again, turned off the truck again, let it sit for a minute and started back up. The "D" light didn't flash again the entire 70 miles home nor has it come on since.
I had changed the tranny fluid about 13 months ago and apparently didn't put enough fluid in (1/2 - 3/4 quart low). I have only put about 11,000 miles on the truck since then. However, my daily commute changed from 50 miles a day to much less than that. Recently, I have also been coming home every day for lunch to let the pup out and feed her. So, I drive 3.3 miles four times a day - which is extremely hard on a vehicle. I'm very easy on my truck when driving, but I rarely get above 35mph. I hadn't noticed any abnormal shifting or roughness recently, but my truck was obviously crying for some attention. I figured I'd go ahead and change the tranny fluid again since it couldn't hurt.
The fluid had only the slightest tint of brown to it, so it wasn't burnt. The mag drain plug had what I would call a normal amount of gray sludge on it, so that didn't alarm me, either. 3.3 to 3.5ish quarts came out and I put a full four quarts back in. After a test drive, I checked the fluid and it was a smidge below the top line (right where I wanted it to be). The truck does seem to shift a little faster and is a little more smooth, but those have been the typical results I've seen after regular fluid changes. The flashing "D" has not returned at all, either, as I said before.
I know this could be a multitude of things like the solenoids or pressure switches, but does anyone think it could have been caused simply by the low fluid or some contamination on one of the switches? The last thing I want to do is take it to the dealership and have them charge me $60-100 in diagnostic time to either tell me there's nothing wrong or that they need to replace a bunch of overpriced parts on a guess. Should I just continue driving and have it looked at if it comes back?
