How to go MAFless

[darcy]

Ian, for yours it's
C2901 = C0301
C2903 = C0303

[IJ.]

Ian, for yours it's
C2901 = C0301
C2903 = C0303

Thanks Mark!

I do have a Gen3 car as well just havn't messed around with it much

[noesfacil]

Joe

Thanks for you quick response.

I checked and all of my C6001 table was set to not reported. Does this mean that the computer never knew that the MAF had failed so it never went to MAP?

Where can I find some info about the different setting options on table C6001? What is the difference in behavior between A, B, C and X?

the mils on C6002 were all set to nomil too.

C2901 is set to 13500 and C2903 is set to 18.

I know my VE tables are all screwy because the PE commanded fuel is not close to actual AFR measured by recently installed serial WB.

So I should first validate that the MAF is actually not working by doing the changes suggested and next step is to do an autoVE so I can get that table corrected?

Thanks again for your time an patience 😊

Jorge

[joecar]

Typo: C2901 rather than C2091, sorry my fat-fingered typing

[joecar]

Joe

Thanks for you quick response.

I checked and all of my C6001 table was set to not reported. Does this mean that the computer never knew that the MAF had failed so it never went to MAP?

Correct... without a MAF DTC triggering, the PCM assumes MAF is still working, and if it is incorrect, the PCM calculates what it should be and uses that.

Where can I find some info about the different setting options on table C6001? What is the difference in behavior between A, B, C and X?

the mils on C6002 were all set to nomil too.

This is a touchy subject due to emissions laws (there are more to these two tables than what is visible), but in simplest form:

C6001: MAF DTC: 1-Trip triggers as soon as MAF fails (see C2901/C2903), Non-Emissions also triggers the same way.
C6002 MAF DTC: No-MIL prevents the MIL from illuminating when the DTC triggers.

C2901 is set to 13500 and C2903 is set to 18.

when MAF frequency exceeds the threadhold in C2901 the number of times in C2903, then fail the MAF (trigger P0102).

I know my VE tables are all screwy because the PE commanded fuel is not close to actual AFR measured by recently installed serial WB.

So I should first validate that the MAF is actually not working by doing the changes suggested and next step is to do an autoVE so I can get that table corrected?

Since your MAF may be incorrect, you can fail the MAF (cause MAF DTC) and run AutoVE to correct the VE table (use EQUIVRATIO * WO2BEN as the correction).

Thanks again for your time an patience 

Jorge

Jorge, no worries.


Note that AutoVE is a subset of Calc.MAFT (AutoVE being olde and using older wideband pids, Calc.MAFT being newer and more general and using newer wideband pids (Calc.MAFT can be tailored to skip correcting the MAF).

[joecar]

So you do have a 2002 (GenIII/LS1B) and not an E38...?

[Taz]

Hello Joecar,

Looks like IJ. (Ian) has an E38 - and jumped in on noesfacil's (Jorge) post, who has an LS1-B. Confused myself ...


Cheers,
Taz

[joecar]

Taz,

Ah, I see, thanks...

Cheers
Joe

[IJ.]

Sorry guys, was looking at new posts and didn't realise what section it was in...

[joecar]

No worries, stuff happens.