Airflow rate from mass air flow sensor (GM.MAF)

[phils01z]

I have been searching and experimenting with my data logs in preperation of logging my wideband data this week. I started playng with my a/d inputs and got my NTK wide band working with some custom PIDs using the information here. I have read that the only sure way to defeat the maf for SD tuning is to unplug it. On my corvette I would have to rig up an IAT. With C2901 C2903 set to "0" when I log GM.MAF I get back only "0". With C2901, and C2903 reset to normal values I get data back during logging. Does this mean that I have effectively disabled the MAF, or just ignored the results?

When I log SAE.FUELSYS I see only "OL. Is there a way to verify that I am running SD and OL ? Also is there any PID that shows PE mode? When I graph PID SAE.FUELSYS all values show as #1.

9141
9143


Thank You,
Philip

[joecar]

Hi Phil,

The MAF is failed when any of P0101, P0102, P0103 show up as current DTC's... when you see any of those then the PCM is running the VE table exclusively.

C2901,3 set to zero should fail your MAF immediately, as long as C6001 has P0101,2,3 set to 1-Trip or Non-Emissions (i.e. not Not-Reported).

OL will be seen when logging FUELSYS (will show OL) and LONGFT1/2 (will flatline at zero).

FUELSYS should show labelled values (e.g. OL, OL-Drive, CL) not plain values (e.g. 0, 1)... check this on the Data tab.

[phils01z]

joecar,

" The MAF is failed when any of P0101, P0102, P0103 show up as current DTC's... when you see any of those then the PCM is running the VE table exclusively."

I assume if this is happening I can simply remove any of the O2s and install my wideband and start logging? I did log the LTFT and they are all flat 0.0 all the time. The DTC was showing codes but I don't recall which ones. I will look tonight.
Thank You,
Philip