I had a very similar problem as encountered by beige2001ex. I had a 2001 Odyssey. About a week ago, I have my MIL on and after a while, TCS light also turns on. However, I exit the highway, the TCS light went off after I restarted the engine. After a while, then it turns on againg (MIL never goes off).

I went to the dealer and got a quick check. I was told that there is an error code P0401 (Insufficent EGR flow). I went to another private Honda repair center, the same code was detected. However, I do not have TCS light for the past few days. I was told it should be Ok if I get EGR valve replaced.

I am not sure that is the whole problem. Hope I do not have a tranny problem.