# Help code 12!



## captkirk (Jan 18, 2005)

I found I have a code 12 from the ECU. 
Haynes had me check for power to the MAF, I have power. Then they had me check terminal "B" at idle and engine off, key on. I got nothing. So, now what?!


----------



## LatinMax (Feb 23, 2003)

captkirk said:


> I found I have a code 12 from the ECU.
> Haynes had me check for power to the MAF, I have power. Then they had me check terminal "B" at idle and engine off, key on. I got nothing. So, now what?!


More info...
Also, normaly the code will be a P#### (with a 4 digit code behind it).
And what year car is it? We know that it is a Maxima, but what year?


----------



## captkirk (Jan 18, 2005)

Sorry, its a '91 and the code I am talking about is from the ECU. I get (1) red light and (2) greens.
The thing is stubbling real bad at around 2000 rpm. 
Air and fuel filter are new. PLugs, wires etc have been replaced.
This is driving me crazy.


----------



## LatinMax (Feb 23, 2003)

captkirk said:


> Sorry, its a '91 and the code I am talking about is from the ECU. I get (1) red light and (2) greens.
> The thing is stubbling real bad at around 2000 rpm.
> Air and fuel filter are new. PLugs, wires etc have been replaced.
> This is driving me crazy.


If you can you need to get to a Auto Zone or somrthing like that and get the actual codes pulled.
But if it won't go over 2000rpm's then it may ne your MAF.


----------



## captkirk (Jan 18, 2005)

There is no check engine light on. Will it still give a code?


----------



## LatinMax (Feb 23, 2003)

captkirk said:


> There is no check engine light on. Will it still give a code?


NO! drive for a little while and see if it gives you a code again (SES light)


----------



## Matt93SE (Sep 17, 2003)

the 3rd gen is OBD-I and very rarely pops a CEL unless something MAJOR is wrong.


according to the service manual, code 12 is the MAFS circuit... And if your engine won't go over 2000rpm, then I'm 99% sure you have a problem with it. that's the typical sign of a dead MAF.

first, check the connection to it and make sure it's good.. After that, there's not a lot you can do with it.

They're around $150 from the parts stores, or $500 from a dealer..
check out forums.maxima.org in the classifieds section for people parting out their cars. you can usually get them pretty cheap there, or go to www.car-part.com for local junkyards and you can get it back up and running fairly quickly and cheaply.


----------



## shock211 (Feb 28, 2005)

I would just try and find a MAF at a wrecking yard. You'll get it for fairly cheap which is nice just in case it's not the MAF causing your issues.
Here's the diagnostic codes in case anything else pops up.


shock211 said:


> ECU Diagnostic Codes:VG30E & VE30DE
> 11 - Crankshaft Position Sensor
> 12 - Mass Air Flow Sensor
> 13 - Coolant Temperature Sensor
> ...


----------

