TCU Part numbers: How to read?

Tonight, I just replaced a 28100 PXO 832 M1 TCU with a 28100 PXO 731 TCU from, allegedly, a wrecked 91 Accord LX. What happens: In Park: No S Light; in R, no S light, N=no S light; D4= S LIGHT IS ON SOLID, but weak; D3 = No S light; D2=No S Light; D1 = No S light. While in Park, depressing the "S" Switch on the gear selector lever DOES NOT activate the S light for Sport Shift (maybe this came from a DX?). Nor does the S light go away in D4 when activated. S light doesn't come on when switch is 'activated' and selector is in D3, D2 or D1. Otherwise, Trans shifts normally and at expected rpm's thru all 4 gears.

So, does the drop from '832' to '731' mean that I'll have problems from the TCU, or that it'll fry, also, in the near future? Is it possible to tell from those 3 digits if a TCU will work well in any given 90-92 accord? Is there some range that one should stay in for each engine/trim level when replacing those buggers?

I think you should be fine.

It's annoying, but that 'S' light is still on after weekend drive to a family reunion in another state. About 600 miles roundtrip, shifted superbly, 1-4 automatically. I had adjusted Throttle Control Cable to the Transmission, also, and had more response to increased gas-feed, when required. Was a very nice trip, considering that on 414.2 mile segment, driven I got around 30 mpg total