Thread: Another #12 fault thread , but voltage checks??

Heya fellas.

Well today I had NissanDataScan hooked up doing some logging in preparation for my dyno tune tomorrow.

I noticed I had 15starts on fault 12. I haven't cleared it since at least half a year now.

My n60 maf idles warm at 1.02v and with motor off ignition on I was showing 2mv. Under wot 3rd gear it was peaking around 4.33 or so.

Any ideas why the fault? Car doesn't hunt really ever, drives great but for if I am in 1st gear and holding < 2000rpms sometimes the car will cut power when i have not moved my foot, I attributed that to my self made tune and mods etc..

Any ideas would be really helpful. I guess all there is to do is clean it with crc, and clean ground but with .2v at acc, I figure my grounds are just fine (re grounded to throttle body).

Thanks a bunch.

Dudeman

Code 12 is set under 2 conditions: 1) With ignition on, engine not running, if MAF voltage is above 4.9V for more than 1 second. 2) With engine running (>600rpm), if MAF voltage is below 1.0V for more than 1 second.

You should clear the code and see if it comes back. While code 12 is set, there are other diagnostics which are not performed.

Dave

That helps tremendously.

I don't see how the voltage could be over 4.5v without their being short or permanent damage.

I drove the car for about 30minutes and didn't visually see it go under 1.02v but if the parameters have been broken then there is no argument.

I am at a loss either the maf is failing or perhaps it is dirty causing it to not be "cooled off" as efficiently as it needs to be thus requiring less voltage across it to maintain temperature.

I reset the code when I first noticed it and it was back within 1 restart.

Clean it tomorrow, there is little else I can do. Again thank you so much.

Dudeman

Alright well today I purchased another used maf from a buddy of mine.

Now both of the mafs I have are .22v under acc. However both when the vehicle is turned on fall between .93-.99 at my idle around 750rpm.

Clearly this is triggering the code immediately. I noticed the idle seemed to get much rougher when the voltage dropped below 1.00v also.

Since my acc voltage is within spec and by a considerable margin, I am going to assume my grounds are perfect and beyond stock.

can anyone else help me verify what the n60 generally idles at?

Thanks for any help.

Dudeman