i've been browsing through the new GM Techline ESI cd i have.

It says
"to do TDCO procedure, run engine until coolant is 170 F.
turn engine off
turn to on w/o starting
floor it for 45 seconds - this resets the PCM TDCO and allows the TDCO to be learned
then turn off for 30 seconds - allows PCm to power down
then start engine
then
as soon as the coolant is 170 F and rpm below 1500 rpm, a new TDCO will be stored.

indicated by a slight stumble. "

also
it seems like maybe this cd set doesn't have everything the 4 book manual has.. maybe it does. i dunno. it does have every vehicle GM makes from 1996 to current, along with repair instructions for all.

for example - it notes GM went to metric engines in 1999. not a bad buy for $30