I bought a used 2018 Odyssey with 148k miles on it. I discovered it had this P2638-torque management feedback signal code but does not trigger the check engine light. I cleared it many times on my diag scanner and it kept coming back. I just didn't worry about it.

Today after 30k miles I have driven it I decided to do a ATF drain and fill. I have the ZF9. I discovered the last place who did the ATF service added one more quart than the spec and they apparently used Valvoline Max-Life because of the reddish color. I put in 3.5 quarts of ATF 3.1 Genuine Honda after draining out a surprising 4.5 quarts and the P2683 is NOT coming up anymore!