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Over the summer I had my car RPM Stage 2 tuned. During the process the car spent about 4 weeks with no ECU. I'm not sure if this is part of the cause, but for some reason now my UltraGauge (nor torque pro, nor carly) can measure MAF sensor anymore. I noticed this because I usually have my UltraGauge set to show me trip MPG, but it can't calculate MPG without the MAF readout. Here's an image of what the UltraGauge is showing:
Does anyone know what could be causing this? I've been assured by the tuner that RPM shouldn't be blocking this output. Could I have a blown fuse somewhere? I don't think it's the sensor going bad because I don't have any stalling issues on startup.
The MAF sensor? Yeah it's plugged in, I'd imagine that if it weren't I'd be having a lot of engine troubles. I've also tried disconnecting the battery and reseating both the MAF sensor and the ECU to no avail
Yeh I drove around with
mine unplugged for about 2 weeks before
i noticed it was never plugged back in
Hell of a lot more
pop’s & bangs
but didn’t throw any codes .
Idk if it’s not thrown
any cels
an it driving fine I
wouldn’t worry about it
who help you at RPM
have a buddy’s o7 setting in my shop now.
Waiting for a stage 3 from them.
he ended up getting
the power gate flash tool.
Instead of sending the ecm out
Yeh I drove around with
mine unplugged for about 2 weeks before
i noticed it was never plugged back in
Hell of a lot more
pop’s & bangs
but didn’t throw any codes .
Idk if it’s not thrown
any cels
an it driving fine I
wouldn’t worry about it
who help you at RPM
have a buddy’s o7 setting in my shop now.
Waiting for a stage 3 from them.
he ended up getting
the power gate flash tool.
Instead of sending the ecm out
Hmm ok. I just did some reading and people are saying that if you unplug the MAF while idling the engine should idle differently as long as the sensor is still good, and it'll be the exact same if it's bad. So I'll try that tomorrow and see what happens.
It's hard to tell exactly the cause. I've got a lot more pops and bangs too, but since this happened the same time I did the RPM tune I'd assume it's the tune causing that. I'm less so worried about the car having issues due to the OBD not reading this and more annoyed that I'm losing my MPG gauge lol
Yeah, that’s a different one. Is your OBD2 port working at all? Is it just boost you are having trouble reading? If it’s not working at all, it may very well be a fuse, that happened to me once when I had my battery replaced, plugged in my scan tool to register the battery and had no power there. Scratch that I see it’s the MAF for MPG not the MAP for boost. My mistake. I still don’t see how the tune can be causing it. I have RPM also. I think at this point you should consider replacing the sensor to see it that fixes it. Or if it’s running fine, maybe just learn not to worry too much about MPG? You do have a tune after all. Drive it hard and you won’t want to know your MPG’s, lol. I’m just joking there, but I seriously doubt it has anything to do with the tune, check the sensor
Yeah, that’s a different one. Is your OBD2 port working at all? Is it just boost you are having trouble reading? If it’s not working at all, it may very well be a fuse, that happened to me once when I had my battery replaced, plugged in my scan tool to register the battery and had no power there. Scratch that I see it’s the MAF for MPG not the MAP for boost. My mistake. I still don’t see how the tune can be causing it. I have RPM also. I think at this point you should consider replacing the sensor to see it that fixes it. Or if it’s running fine, maybe just learn not to worry too much about MPG? You do have a tune after all. Drive it hard and you won’t want to know your MPG’s, lol. I’m just joking there, but I seriously doubt it has anything to do with the tune, check the sensor
Yeah the OBD works fine for all the gauges I used to use except for this one. I don't think it's the tune that's causing it either, I'm just not sure what it could be.
MAF may be broken..so car is in open-loop/WOT mode and using ECU fuel tables ... NOT measuring LAMBDA.
**The above is why your mileage sucks. Pickup a new MAF sensor to swap in.. see if your readings come back after.
Is there a way to diagnose the MAF sensor definitely? My mileage hasn't changed dramatically and when I unplug it while running, the engine does change the idle slightly -- it doesn't get horrible, but there's a slight change. I'd rather not spend hundreds of dollars on a new MAF that I don't actually need.
There has to be ways to test it. BigBoost above has it there. Just need to know what you’re looking for..... I’m not exactly sure if I could do it without a tutorial, but I’m not exactly electronically inclined, lol. Good luck. I didn’t realize that the MAF is pricey to replace, but that’s not surprising. Most everything OEM on these is a bit on the spendy side.
Ok so I pulled the plug on the sensor again and tried to drive this time. It stalled almost immediately, so it's definitely different with the maf unplugged. I've got a multimeter that senses frequency on the way, so I'll test out the signal wires when I get that. Otherwise, I guess my options are to either deal with it (and the possibility of other things not working that I'm not aware of) or taking it to the dealer. It's hard to tell what's wrong because I had the ecu out for a month or so while I was out of state and getting it tuned, so it could be just about anything.
Hmmm...interesting. I usually actively avoid thinking about mpg because my car, especially since Mario tuned it, totally brings out my inner 13 year old, lol. And I know I’m getting terrible mileage. But I’m having way more fun this way. Aside from it not reading through the OBD2 port, there are no other symptoms or codes? I still can’t help but think there must be something with the sensor or plug/wiring that is causing the problem, since the obd port is working for everything else.
Nope, nothing else that I can see isn't working. No trouble codes (or pending trouble codes) that I can find. It seems to be running perfect. I usually like to see my mpg for long trips, but it doesn't really matter that much to me -- smiles per gallon is much more important. With that said, is there anything I should replace the gauge with? I've currently got boost PSI, coolant temp, outside temp, intake temp, mpg srt, and miles srt. I also might hit up a friend and see if he'd let me try to swap in his MAF sensor to see if that changes anything.
Of all the combinations, I was able to read a frequency if I put the test leads between the orange and yellow wires.
Here's a video of me revving and the resulting frequency output: https://photos.app.goo.gl/bvTjXaiaGNEXotCW6
In the video, it looks like the voltage is related to the RPM, but it's also jumping around a lot. I'm not sure if this is expected, or if it's the MAF's fault, or if it's the multimeter's fault.
Does anyone have any insight given this data?
I think I've got it set right.
In the second video the guy says there will be a constant voltage (5 or 12v), constant ground, signal wire, and sensor ground.
So in my case, it seems the blue wire was constant voltage (@5v), white wire was constant ground, orange wire was signal wire(@12v) and yellow wire was signal ground.
Since the R56 uses a hot film type MAF sensor, I should be using the Hz monitoring between signal wire and signal ground (orange and yellow).
Am I wrong in these assumptions? I'll have to go back and measure the terminals when it's not connected to the MAF to validate this.
08-31-2018, 06:23 PM
