Magic Chicken

iTrader: (1)

Can someone please explain exactly what the difference is between FTC 15 and 22. I am finding that all of my 100% TPS runs are in 15. On my last log, I hit 22 between 0-61% TPS. Are there pros/cons to this behavior, or is it just normal?

Thanks.

deezel

Trucks seem to use cell 15 for WOT and cell 22 only for a few open loop, non-PE conditions. Cell 15 is a normal fuel trim cell defined on the Main VE table by the fuel trim boundaries (MAP>77kPa, RPM>2200). Cell 15 can have + or - fuel trims in closed loop and will lock to 0 in OL if CL trims are negative. Cell 22 is an open loop only condition where the evaporative purge solenoid is operational. I see very little of cell 22 and lots of cell 15.

Magic Chicken

iTrader: (1)

Would there be any advantages or disadvantages or would it cause any problems to change the fuel trim boundaries say to 1200, 1600, 2400 and 35, 55, 80?

jimmyblue

iTrader: (11)

I have changed my boundaries, although to somewhat
different values (I went with 1000, 2000, 4000).
Basically one row is wasted on idle, but the other
three are light cruise, medium cruise and up-on-the-
converter.

I have detected no issues from this. I did it at the
time of my last MAF swap.

Bink

Here you go ....read this thread for some excellent info...... hope this helps some.


FTCs

joel