The pesky P0101
I've had the P0101 code for quite a while, saying "Mass or Volume Air Flow Circuit Range Performance." I am stumped and unable to figure it out. I've done a bunch of reading on the issue and would really appreciate some input.
Things done so far:
- Had a mechanic go over wiring to make sure it was all ok. (He also hooked it up to his scanner and told me that when under load the ECM commands a negative value of air intermittently. Not sure what that could mean)
- Used a known good MAF sensor.
- Replaced ECM
- Pressure tested all the turbo lines. (Had a couple leaks, but fixed now)
I now have the EGR valve and cooler off, but to be honest, I don't really know what I'm looking at. I know that it potentially could be the issue, but don't know how to tell. The valve does move when a vacuum is applied. I also don't know if it could possibly be one of the other sensors. Anyone will some knowledge and input on the issue would be greatly appreciated. Also, I'm in California and need to get it smogged, but am unable to until i get this code taken care of.
2002 Chevy Silverado 2500HD