Do these low values indicate faulty MAF’s?
11-16-2018, 09:41 PM
#1
Do these low values indicate faulty MAF’s?
Hello all,
I have an 04 CTT with 128,000 miles. I picked it up with 115,000 miles, so some of its service history is questionable at best. Today I threw the PSM and ABS failure lights. I did a lot of googling during the day, which indicated several possible theories. However, when I got home and scanned with the Durametric, the only codes were for the front left wheel speed sensor, in both the transmission and stability management modules. So it seems pretty clear that was the original issue.
However, while I was in there, I looked at the readings for the voltage and flow measurement for the mass airflow sensor‘s. My quick research showed that numbers around 20 kg/h at idle and 60 around 2500 RPM seemed like good values. Unfortunately, my flow measured around 5.7 to 6.0 kg/h at idle, and 19.8-21 at 2500 rpm with no load. The voltage for each side was steady at 1, and increased incrementally to 2 and above with increased RPM’s. My question is: do those flow numbers specifically Indicate any faults with the MAF’s? I haven’t thrown any codes for airflow or the MAF specifically, but those numbers don’t gel with the comments I had to read and other threads.
Thoughts and advice?
Thank you,
Jeremy
I have an 04 CTT with 128,000 miles. I picked it up with 115,000 miles, so some of its service history is questionable at best. Today I threw the PSM and ABS failure lights. I did a lot of googling during the day, which indicated several possible theories. However, when I got home and scanned with the Durametric, the only codes were for the front left wheel speed sensor, in both the transmission and stability management modules. So it seems pretty clear that was the original issue.
However, while I was in there, I looked at the readings for the voltage and flow measurement for the mass airflow sensor‘s. My quick research showed that numbers around 20 kg/h at idle and 60 around 2500 RPM seemed like good values. Unfortunately, my flow measured around 5.7 to 6.0 kg/h at idle, and 19.8-21 at 2500 rpm with no load. The voltage for each side was steady at 1, and increased incrementally to 2 and above with increased RPM’s. My question is: do those flow numbers specifically Indicate any faults with the MAF’s? I haven’t thrown any codes for airflow or the MAF specifically, but those numbers don’t gel with the comments I had to read and other threads.
Thoughts and advice?
Thank you,
Jeremy
11-16-2018, 11:37 PM
#3
11-16-2018, 11:50 PM
#4
I'll have a look at my total flow tomorrow to compare. I recall my voltages each being below 1V at idle though, so that one seems ok.
How's it driving, any signs of performance issues? You can always unplug your MAFs to see if there's a difference. Mine is running smoother with the MAFs unplugged because I suspect I have one that is bad, it reads lower than the other one.
How's it driving, any signs of performance issues? You can always unplug your MAFs to see if there's a difference. Mine is running smoother with the MAFs unplugged because I suspect I have one that is bad, it reads lower than the other one.
11-17-2018, 09:10 AM
#5
I’ve always has dismal MPG’s since I bought it; in the 12-14 range, even on the highway. I just thought that came with the territory. I also experience less-than-smooth running around town when cold (cold start, not temperature). I’ve replaced all the coils and plugs and several old vacuum lines. Car doesn’t and hasn’t thrown any codes that would indicate MAF, I’m justbwondering how much of an impact they could make before triggering a code
11-18-2018, 12:23 AM
#6
I didn't get around to looking at values today, hopefully in the next few days.
From what I've experienced and heard, you're more likely to get a MAF code from a vacuum or boost leak than from a bad MAF.
I have one MAF reading quite a bit lower than the other (I also found oil on that side) but I've yet to get a MAF code from it.
Did you disconnect them and drive around yet?
From what I've experienced and heard, you're more likely to get a MAF code from a vacuum or boost leak than from a bad MAF.
I have one MAF reading quite a bit lower than the other (I also found oil on that side) but I've yet to get a MAF code from it.
Did you disconnect them and drive around yet?