Low MAF Freq
Thread Starter
Teching In
Joined: Dec 2005
Posts: 46
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From: Lady Lake FL
Low MAF Freq ok i'm lost at this. i havnt had any problems at all with my MAF sensor until this last reflash. now its throwing this code and kicking the whole thing over into SD. i know some people love SD but here in fla i would much rather be using the MAF. my question would be, would the MAF just all of a sudden take a crap? or is there somewhere in the programming that i can adjust when it determines this? i've tried resetting it a few times and it keeps coming back. when i scan it, it will show 0 g/ps with the engine off but as soon as i start it, it jumps to and stays at 4.89 g/ps.
It could just take a crap, but you can swap with someone and see if that fixes it and if it does then you need a new maf sensor. If it doesn't fix it then there is a wiring issue some where. I had this problem with my Suburban just recently. The o2s wires were rubbed through and it grounded out, causing the ses light. If this is your case, then you could have a similar wiring problem. I'd switch the maf sensor out with someone first before you have to go through the headache and HOURS of searching finding multiple other things wrong.
This is maybe one of those codes that's about
multiple personality disorders, the MAF and the
speed density airflow values are enough out of
sync to trouble the PCM. There is a bitch-threshold
value you can modify, or you can work more on
getting Heckel and Jeckel to agree (preferably
agreeing, along with the more accurate of the
two).
multiple personality disorders, the MAF and the
speed density airflow values are enough out of
sync to trouble the PCM. There is a bitch-threshold
value you can modify, or you can work more on
getting Heckel and Jeckel to agree (preferably
agreeing, along with the more accurate of the
two).
Thread Starter
Teching In
Joined: Dec 2005
Posts: 46
Likes: 0
From: Lady Lake FL
well the problem with switching with someone around here isnt going to help. i dont know anyone close to here that would let me try theres.
but jimmy, i just got to thinking about it, i redid my RAF tables and they dropped quite a bit from what they were at. should i try and redo the bottom end of my sensor now seeing as how there is a difference of about 5 grams between calculated and what the MAF was tuned at? if not, where is the bitch-threshold at? it was doing good up until this point, which really sucks cause the racing season starts sat. and i was wanting to get some final t&t tonight(wed) at the track.
but jimmy, i just got to thinking about it, i redid my RAF tables and they dropped quite a bit from what they were at. should i try and redo the bottom end of my sensor now seeing as how there is a difference of about 5 grams between calculated and what the MAF was tuned at? if not, where is the bitch-threshold at? it was doing good up until this point, which really sucks cause the racing season starts sat. and i was wanting to get some final t&t tonight(wed) at the track.
At idle the MAF should be a pretty low contributor
to the dynamic airflow value. Seeing 0 says it's all
speed density (MAP*RPM with RPM=0) because the
MAF ought to be putting out 1500-2500Hz (I see
2500 on the 85mm Delphi, open face in still air) and
make a real (not to say correct) airflow number. If
you look at the logged frequency what do you see?
Look in Engine Diagnostics, P101 and maybe others
are in the Airflow tab. Seems to vary some by the
model*year. What PCM & OS are you swapped onto?
Or is this the truck?
Which code is popping, number?
to the dynamic airflow value. Seeing 0 says it's all
speed density (MAP*RPM with RPM=0) because the
MAF ought to be putting out 1500-2500Hz (I see
2500 on the 85mm Delphi, open face in still air) and
make a real (not to say correct) airflow number. If
you look at the logged frequency what do you see?
Look in Engine Diagnostics, P101 and maybe others
are in the Airflow tab. Seems to vary some by the
model*year. What PCM & OS are you swapped onto?
Or is this the truck?
Which code is popping, number?
Thread Starter
Teching In
Joined: Dec 2005
Posts: 46
Likes: 0
From: Lady Lake FL
well my brother is off with the laptop so i'll get the freq in a little while. but its throwing the p0102 code. its a 98 computer and stock OS. i played with the dynamic airflow table a while back and have it set to use the filtered MAF signal after 1000. my cam doesnt have much, if any, negative pulse at idle.
11 Second Club
Joined: Jun 2005
Posts: 1,537
Likes: 0
From: Was New Orleans, but swam to Baton Rouge
If it was a P0101 code I would suggest modifying the MAF Delta table. Since it is not that code and a P0102 code which is a MAF low voltage I think a replacement or wiring issue whould be affected. There is no reason to change the MAF calibration table of Hz to g/s unless you change to a different MAF.
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Verdad Gallardo If you have a voltmeter check the +12V and "+5V" (output)
wires against the black ground wire. +12V comes off the
ENG SEN fuse I believe, the +5 is the PCM's pullup source.
It may be a power rather than a signal problem.
wires against the black ground wire. +12V comes off the
ENG SEN fuse I believe, the +5 is the PCM's pullup source.
It may be a power rather than a signal problem.
Originally Posted by jimmyblue
If you have a voltmeter check the +12V and "+5V" (output)
wires against the black ground wire. +12V comes off the
ENG SEN fuse I believe, the +5 is the PCM's pullup source.
It may be a power rather than a signal problem.
wires against the black ground wire. +12V comes off the
ENG SEN fuse I believe, the +5 is the PCM's pullup source.
It may be a power rather than a signal problem.
Originally Posted by kamikazematt
thanks a ton jimmy. i checked them and i wasnt getting a 12v signal so i looked at the fuses and found that it was blown. i'll add that to my list of "off the wall b.s. fixes".
