trophystock

I have a 99 C5 and when I unplug the MAS and set the MAS frequency fail to "0" I do not get a check engine light. The scanner will read 0.32 #/min of flow at all times. What am I doing wrong?

405HP_Z06

iTrader: (11)

Have you drive cycled the car a few times? Sometimes it takes a while for the PCM to recognize the failed MAF sensor.

Magnus

iTrader: (4)

In VCM Editor in the DTC display make sure you have your MAF DTC's (maf HI and Lo freqencies) set to report an error on 1'st error.

If you disable the MAF DTC's in the editor, you will not set them even if you set your maf fail to 0.

As long as your MAF DTC is set correctly to error on the 1'st error, you can set your MAF fail to 0 and don't even need to unplug it.

- Keith, HP Tuners

trophystock

I checked the DTCs and found that the MAS fails were set on "1" so I changed that to "0" and will go check it.
Charles

trophystock

I wonder why it reads 0.32 all the time and not 0?

trophystock

I assume I should see a check engine light right after I start the car up?

405HP_Z06

iTrader: (11)

It takes mine a few minutes to fail. Start it and drive and it should fail for you. Do you have P0103 turned off?

trophystock

no i donot have it turned off. I am still wondering why with the MAS unplug I still get a value of 0.32 #/min?

Black02SS

iTrader: (36)

I have found on a few cars that setting the fail to 0 doesn't work all the time. My best bet is what Keith suggested to a degree, unplug the MAF, keep everything else the same, except set the DTC to error on 1st attempt for codes P0101, P0102, P0103.