[RESOLVED] CEL - 12 Volume Air Flow Sensor...now what? With 13 and 25 now!

[Ice Racer]

So I rigged up an ECU diagnostic tool with alligator clips and LED I had lying around (worked great ). I got code 12: Volume air flow sensor. So now what? I mean, what is it telling me? Do I need to replace it? Where is it exactly and what does it look like?

 

[BoostedTalonTS]

It is your MAS... I would double check that it is plugged in, then try an ECU reset. -If the code comes back again I would look into replacing the MAS.

Reset the ECU by removing the "BATT" fuse from the engine bay passenger side fuse box (or just pull the battery positive terminal)... Wait for 15 seconds and plug it back in.

Then start the car and look for CELs... if none, drive it around for ~10-15 minutes then check for codes again.

BTW, you can use any standard voltage or ohm meter to conduct the same test.

 

[Ice Racer]

MAS is definitely plugged in. It's not hacked btw (i.e. lower honeycomb is installed). I cleaned the connector with BrakeClean just in case it was dirty but no change.

Also tried the ECU reset and still CEL.

Ugh, seriously? New MAS? I just bought the damn car 5 days ago...

I guess this is my "Welcome to DSM" package.

 

[BoostedTalonTS]

Well before you go replacing the MAS, I'd also check the ECU's wiring... If the car ever had an AFC in it, the MAS signal wire would have been cut... It's possible that someone could have just cut out the AFC and never reconnected the factory wiring back together... Use the AFC wiring diagram found HERE to double check that everything is hooked back up to factory as it should be.

If you are still getting a CEL then it's more then likely a bad MAS... Find a local DSMer that can loan you one for testing, just to further rule out any other possibilities.

 

[Ice Racer]

BoostedTalonTS, The car came with S-AFC II installed and I wasn't getting the CEL when I first bought the car about a week ago now. This just sprung on me recently so you're right in that it's either a faulty connection that jarred loose or a bad MAS.

 

[Ice Racer]

Well...tried a few things. Fooled around with the MAS plug in case it was corroded or maybe "lost" connection. Who knows... Then tried to reset the ECU codes by removing the negative terminal for 10 seconds. Nada - codes still present. But guess what, now I have a side dose of codes 13 and 25. Ugh, what gives?

This sounds like a bad connection :crossing fingers: rather than a bad MAS. Thoughts?

 

[Ice Racer]

If anyone cares, it was a setting in the S-AFC II for the sensor choice. Should have been set to Karman and it appears it was set to something else. All CEL cleared and revs freely now.