What will happen if I continue to drive Honda 2003 Odyssey with code p0730 present?

Question

My Honda 2003 Odyssey suddenly started showed the "check engine light" and the "TCS" light (intermittently). It has 150K miles (easy freeway miles with little accelleration and no towing), so my wife took it to Honda for diagnosis. They declared the transmission should be replaced.

When I checked the OBDII codes, it showed P0740 and P0730. I reset the codes and they didn't come back. The car drove fine, in all gears, at high load and light load, accellerating or not, for about 5 mi. Then after about 5mi troublefree driving at ~50mph on the flat, as I accellerated up a ~5% grade, the "check engine light" and the "TCS" light came back on. At the same time, the tranny started to fail to shift to higher gears, and over rev (apparently failing to engage into the upper gear). I limped home, barely able to maintain 40mph, then 35mph, irrespective of what gear I put the tranny in.

When I got home, I looked at the OBDII codes, and it showed P0740 and P0730. I reset the codes, and they remained gone, and was able to drive around town (30mph on the flat) without any issues.

It has tranny fluid levels that are full, and the fluid has no visible particles suspended, and a pale transparent amber color (no significant burnt smell). Basically looks fine.

Answer 1

P0740 Problem in  the TCC

P0730 Problem in  the  shift control system

With these 2 code it is highly recommended you replace or rebuild the transmission, The worst that can happen is the transmission fails all at once and leave you stranded.