P0102 under boost. Why? Help!!
03-19-2006, 12:59 PM
#1
P0102 under boost. Why? Help!!
I keep getting a P0102 code when i get into boost. The MAF goes all the way up to 60.45lb/min and the map reads 103. then, immediately the maf goes to 0.22 then back down. The truck falls flat on it's face hard, almost like then engine was shut off.
I was told to check the map sensor. No idea where it is.
I was also told to check my vacuum lines. I found one hose that goes from the passenger side valve cover to the top of the intake manifold. The valve cover side looks like it has some oil around the bottom of it. I reached under the blower and grabbed the hose. It pulled right out of the cover with no effort whatsoever. Any idea what that is?
Where else do i look for vacuum leaks?
Again, I ONLY get this problem when the maf is hooked up and when I get into boost. The maf is functioning fine as far as i can tell. I actually took the one out of my buddy's avalanche to test it and got the same results.
I was told to check the map sensor. No idea where it is.
I was also told to check my vacuum lines. I found one hose that goes from the passenger side valve cover to the top of the intake manifold. The valve cover side looks like it has some oil around the bottom of it. I reached under the blower and grabbed the hose. It pulled right out of the cover with no effort whatsoever. Any idea what that is?
Where else do i look for vacuum leaks?
Again, I ONLY get this problem when the maf is hooked up and when I get into boost. The maf is functioning fine as far as i can tell. I actually took the one out of my buddy's avalanche to test it and got the same results.
03-19-2006, 01:16 PM
#2
P0102 is the MAF Sensor Circuit Low DTC. It is set when the MAF sensor frequency drops below the MAF Low Frequency Fail value more than the number of times specified in the MAF sensor frequency fail limit.
I don't see how the MAP or a vacuum leak would affect this DTC.
I don't see how the MAP or a vacuum leak would affect this DTC.
03-19-2006, 01:18 PM
#3
Do you still have the Whipple electronics installed? If so, it could be the problem. The Whipple computer intercepts MAF. You can't really bypass this, even for testing, because your auxiliary injectors won't get any fuel. (Still asuming you have the Whipple Electronics.)
03-19-2006, 01:40 PM
#4
no whipple electronics. everything has been working great. it started after i put a ported tb on (stock one is back on now) and after I got the truck back from the audio guy who upgraded my audio system, moved my heater controls, and cleaned up some wiring under the hood. he didn't touch the pcm or the maf though.
03-19-2006, 01:45 PM
#5
i was just comparing to logs. one from when everything worked great, and one from now.
the maf then only went up to like 42ish. Now, 60ish.
the O2 sensors then were 920ish at WOT, now i can't go WOT but at 70% throttle they read 0. what the hell?
the maf then only went up to like 42ish. Now, 60ish.
the O2 sensors then were 920ish at WOT, now i can't go WOT but at 70% throttle they read 0. what the hell?
03-19-2006, 07:36 PM
#6
The "cleaned up some wiring under the hood" part is a little scary. What did he clean up?
Couple of things I see: 1) your MAF readings show 60.45 and then hit 0.22 (which is what my MAF reads -- interesting since my MAF is on someone else's truck
) I'm assuming 0.22 is a fail setting in the PCM (the minimum MAF reading that can be reported with power on) since I have no MAF at all and read the same flow. 2) Your nbo2s read 0mv... The only way that could happen is bad O2s, which should be throwing codes left and right, or something kerplunked in the PCM or harness. 3) your MAF readings have jumped up 50% with no additional flow.
Since you are seeing problematic results from two very seperate sensor packages, I'd be looking at the electrical system (check grounds, fuses, possible shorts) and the PCM.
Couple of things I see: 1) your MAF readings show 60.45 and then hit 0.22 (which is what my MAF reads -- interesting since my MAF is on someone else's truck
) I'm assuming 0.22 is a fail setting in the PCM (the minimum MAF reading that can be reported with power on) since I have no MAF at all and read the same flow. 2) Your nbo2s read 0mv... The only way that could happen is bad O2s, which should be throwing codes left and right, or something kerplunked in the PCM or harness. 3) your MAF readings have jumped up 50% with no additional flow.Since you are seeing problematic results from two very seperate sensor packages, I'd be looking at the electrical system (check grounds, fuses, possible shorts) and the PCM.
03-19-2006, 08:04 PM
#7
ok, he did move some ground wires. i'll have him look thru it again and show me exactly what he touched. I just can't imagine what he could have touched that would cause this. makes no sense. the only wiring he touched was for my boost gauge, fuel pressure gauge, methanol injection.
hmm, maybe some of the wiring from the previous whipple "piggyback" has finally reared it's ugly head. When i got rid of the piggyback i had to piece the pcm back together. I wonder if he tugged on something just right and f'd up those wires? Now that i think of it, one of those wires was for the MAF.
hmm, maybe some of the wiring from the previous whipple "piggyback" has finally reared it's ugly head. When i got rid of the piggyback i had to piece the pcm back together. I wonder if he tugged on something just right and f'd up those wires? Now that i think of it, one of those wires was for the MAF.
Trending Topics
03-19-2006, 09:49 PM
#8
This may sound simple but, I just pressure washed my truck a week ago and had the same code come up.
I thought I had got the filter wet again and sucked water up into the intake, but the wires going to the MAF were wet not the inside of the MAF.
I dried all the wires out and put dielectric grease in the connection and it ran fine, the code cleared and did not come back up.
I hope you get your issues fixed soon. It suckes when you don't know or can't track down the Gremlins.
I thought I had got the filter wet again and sucked water up into the intake, but the wires going to the MAF were wet not the inside of the MAF.
I dried all the wires out and put dielectric grease in the connection and it ran fine, the code cleared and did not come back up.
I hope you get your issues fixed soon. It suckes when you don't know or can't track down the Gremlins.
Thread
Thread Starter
Forum
Replies
Last Post
06murder
Tuning, Diagnostics, Electronics, and Wiring
2
09-04-2015 03:54 PM
