I mistakenly thought steering wheel angle neutral position had something to do with the steering wheel angle. It does not. If anyone has that problem after disconnecting their 12V battery there are there are two learning methods. One with HDS and one without:
From all of the posts it seems there are three things being discussed that can be off: steering wheel off-center, steering wheel angle, and steering wheel angle neutral position. The situation that people are reporting here all seem to be related to steering angle.
- Steering wheel off-center. From one of the sources that you quoted: "If the steering wheel is off-center by a large amount (20 mm or more), it may not be centered on the steering column shaft. Reinstall the steering wheel before going to step 2."
- Steering wheel angle. Requires adjusting tie-rods etc. The situation that people here have experienced.
- Steering wheel angle neutral position. This seems to be the subject that a large part of your posted sources are referring to. As far as I can decipher based on the sources as well as all of our experiences, it is normal or at least common for the steering wheel angle neutral position to get cleared when the battery is disconnected. The system then self corrects as soon as there are ten seconds or so of straight line driving. No action is required by the driver other than driving the car.
The steering wheel angle neutral position needing to be cleared apparently accounts for several of the normal error messages seen when the car is first driven after battery disconnect. Quite interesting, I was not aware of that.
Your posted document mentions that two learning methods for steering wheel angle neutral position are available after battery disconnect. The first method is to simply drive the car in a straight line for ten seconds. That of course is the method used by owners as it seems that normal driving sets it pretty quickly.
The second method is to use HDS, which is Honda's diagnostic system used by dealers and also independent shops who subscribe to it. My guess is that the HDS method is useful for a mechanic as a way to reset the steering wheel angle neutral position without having to take the car out for a drive, as might be the case when doing a repair that does not otherwise need a test drive upon completion of the repair. In theory it could also be used in cases where driving does not set it, but I have never heard of anyone experiencing that, someone would have to live somewhere with extremely curvy and bumpy roads for that to happen.