I suspected the TCS might be using vacuum. If this is the case, however,
why would a clogged EGR system be the souce of the error. If there was a
vacuum loss, then a drop in EGR flow might be a symptom of the vacuum loss?
If the EGR flow is restricted, the vacuum should increase if everything else
stays the same, should it not? I assume that EGR flow is into the IM, not
the other way around. Maybe the TCS shuts down with any engine malfunction?
Is this stuff covered in the service manual or is there additional training
literature?

I have seen enough posts on various forums to make me wonder how reliable
the codes on Hondas of this era might be. I work on electonics and know how
something as simple as ground integrity or a little noise can affect a data
bus or corrupt an EEPROM. I am wondering if there is a problem at all. At
about the same time that the engine and TCS lights came on I had a strange
control problem in the AC. The modes would not switch and it came on in the
defrost mode instead of the normal auto mode. None of the problems have
occurred again. I'll plot the data on the fuel economy today and see if
there are any changes there, but an initial look indicates no problem.

Leonard

"Genboy" > wrote in message
ups.com...
> Agreed, the TCS comes on the same time as the check engine light for an
> EGR flow problem, mainly because the TCS also uses vacuum pressure.
>