Programming 101

[Bruce Plecan]

The purpose of this posting is the understanding of engine management, as
used by gm in the 1227747 ecm.  The Prom Mask is 42 as found at 0004.
If you attempt to use any of this informaton for modifing a vehicle, be
aware that you can ruin a pefectly good engine in a matter of seconds, by
experimenting.  If you can read a spark plug, or have't read the tuning
tips, please don't try to use any of this info..  Changing any of this in
your location may be illegal, and may only be used in off road conditions.

While the ecm has a capacity for Hearing detonation, the recovery rate is
slow so as to allow the engine to recover "smoothly".  While maybe not an
ideal chose of words, it does min, crank speed variances.  Anyway, there
needed to be a very fast acting way of preventing detonation, during sudden
TPS changes, or acclerations.  They do that at 002E-0031.
E being MAP Threshold
F TPS
0 Diff TPS
1 Duration
The degrees for the above are referenced at 0167-016C as a function of CT
Starting at 010A is a table 12x5 that seems to be a spark vs coolant temp..
The EGR SA (Spark Advance) vs EGR correction is 0146 thru 0156
At 01C4 starts a table 7x7 for EGR, then another EGR string at 01F6
At 0220 is another EGR related table that is 13x8
Closed Loop Timer is warm or cold and the temp is at 0296, and warm timer
is 0297, and cold 0298.
02AA is stoich
If you'd care is take issue with any of this please write me off line, and
then
we'll figure out my errors..
Also, please change the heading when respondiing so we can keep this
searchable in the archives.
Bruce         nacelp at bright.net