What should be checked first?
I keep the trans fluid changed.
Trans shifts fine like normal, just not into OD. No hard, or delayed shifts.
Driving around town you would never know something is wrong.

 

I had limited time today, but

I drove it to the store, and back home (about 7 miles 2 stoplights). The temp gauge doesn't seem to get up to temp like before. When I was stopped at light the temp started climbing, but when I took off the temp started to come back down.
Thermostat must be stuck closed. When I got back the upper radiator hose was warm/hot, but the lower radiator hose going to the thermostat was cold.
So, guessing there is no coolant going through for the temp sensor to read to let computer know motor is warm to shift in OD.

 

And/Or you have air in the system. did you try bleeding?

 

Yes, I tried bleeding the system.

When idling the gauge raises to normal temp, both radiator hoses are hot, and it cycles, BUT the fans are not coming on.
I will order the temp sensor on the thermostat housing. This is not the problem for dropping temp going down the road I wouldn't think.

It will idle up to normal temp, then driving down the road the temp goes colder than normal.
I always thought this meant thermostat bad.

What are the causes for the temp to read below normal operating temp going down highway?

 

If the temp gauge reads normal when stopped, but then drops as soon as you begin to move, then it is most likely the thermostat that is stuck open(fail safe).
Replace the thermostat.
Also when the engine is cold the transmission will not go into 4th.

 

That was the first thing I did was change the thermostat. I used a factory honda thermostat
When I was changing them I actually got them mixed up. So, I put both in a pot of hot water, both opened, and then closed when I took them out.