Sensors with circuit high voltage

Welcome to 2CarPros,

Two items can cause this easily. One would be if all six are fed with the same voltage source (very common) and the feed wiring gets shorted to battery voltage. Another item would be if the same sensors are grounded to the same point and that fails. This would mean the ECM would see them as high voltage because it no longer has the ground as a reference.
This does not mean that those sensors are bad.

If you can post the exact codes or which sensors are the issue it would be easier to determine which is the more likely situation.
Looking at the wiring diagram I see that many of the items you mentioned share a common ground point. The green with yellow stripe wire which is a sensor ground #2, that wire is shared among the B1S1 O2, EGR pos, input speed sensor, intake air temperature, engine coolant temperature sensors, ATF temperature sensor all go to pin 14 in connector C on the PCM. It is also the only sensor ground terminal with that many sensors.
However, Honda used that same color wire for other grounds as well so knowing which sensors to look at first will help.

The codes are P0123, P0223, P0113, P0155, P0108 and P2631.

Also, is it possible that a bad battery or a battery with a low charge could cause this?

I would check the alternator to make sure the voltage is not excessive or low. Here is a guide:

https://www.2carpros.com/articles/how-to-check-a-car-alternator

If that checks out lets follow this guide to check the system grounds at the PCM. Also check the PCM relay.

https://www.2carpros.com/articles/how-to-check-wiring

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Check out the diagrams (below). Please let us know what you find.

Cheers, Ken

Alternator checked out fine but the battery did test "bad" with a low charge. I replaced the battery and erased the codes. I have driven about one hundred and fifty miles since I erased the codes and so far so good. Check engine light has not come back on and van seems to be running good.

Hmm, missed your earlier reply, Sorry about that. It is possible that a bad battery can cause battery related or other codes, especially with modern vehicles as the battery voltage is used as a reference item by the various modules.