How are the BLM cells numbered? If there are 16 cells, why do the boundary parms only allow 3 values per axis, that would only be 9 cells unless 0 is assumed on both, but I would think your idle speed should be the lowest on the RPM axis? * If my KPa boundary is 25, 50, 80 And my RPMs are 700, 1200, 2000 How would the cell# correlate in the table below? .........25 50 80KPa --------------------------------- 700 . | ?. ?. ?. 1200 | ?. ?. ?. 2000 | ?. ?. ?. Or if 0 is the default low value for each...my guess is they are numbered as follows: .......... 0 25 50 80KPa -------------------------------------------- 0..... | 0. 1. 2. 3 700.. | 4. 5. 6. 7 1200 | 8. 9. 10 11 2000 | 12 13 14 15 Is that right? Thanks

I have an 730/8D, and the BLM array is close your second choice:


kPA ....|................................RPM
................0-850...... 850-1600.....1600-2400......>2400
>75............12.................13..................14...............15
50-75...........8...................9..................10...............11
25-50...........4...................5....................6.................7
0-25.............0...................1....................2.................3

As you can see, the cell# advances through an RPM range before
moving up to the next kPA level. My 730 idles in cell 4, at 725 RPM and about 35kPA.
Hope this helps you--

my BLM cell MAP boundries are

low.............25
med............50
high............75

Cell RPM's are

low...........1000
med..........1600
high..........2400

and that is for a 730 ECM $8D why are mine so different? and how be these be numbered??

That's coincidental. Cell 4 is the "idle" cell by default. You can change those MAP/RPM boundaries till your blue in the face, it will still idle in Cell 4.

This is because there is actually a "variable" that you can select the Idle BLM cell to be on the 7730. By default, it is Cell 4.

Actually, Glenn91 said it: The cell boundries can be changed (or originally different from GM), but the "Idle" cell seems to always be 4. Your cells are identical to mine except for the lower RPM, where mine is 850, while yours is 1000 RPM. A minor change in the code.
The cell #s would be similar to mine, i.e., 0 is 0-25kPA& 0-1000 RPM, 1 is 0-25kPA & 1000-1600RPM, and so forth.