# P12A2 Error



## MLue1 (Apr 27, 2008)

Anyone gotten this code and fixed it?



Two days ago my wife reported that the CEL was on, when I read the codes error code P12A2 flashed up. I cleared the code but it returned a day later.



According to the web, P12A2 is related to the fuel rail pressure sensor high, the info that I read indicated that others have replaced the fuel rail pressure sensor but to no avail. No vacumn leaks are evident.



I have noticed that when idling that the engine appears to sputter, so I'm thinking that the fuel pump maybe the cause.



Thoughts?


----------



## MLue1 (Apr 27, 2008)

…. no responses (_disapointing…)_, I guess I'll go it alone.

I read a couple of other current posts going on which reference the fuel pump as the cause but none indicate the P12A2 error code, so hopefully it's the sensor and not a pump.

I've read and cleared the codes using my Innova 3100 ODB reader or my ELM327 and my Galaxy Smart phone running the Torque (free) app. Both read the same P12A2 code, it's interesting that the ELM setup costs under $10.

I've noticed a few things:
1) when I clear the code the engine stumbles as it idles
2) when the CEL is on the idle is smooth
3) engine still pulls quite well with or without CEL on
4) new code popped up last night P0171 - engine lean condition, this points back to a pump once again 

I'm researching replacing the sensor my self… .


----------



## ebios (Jun 9, 2014)

*Have the same fault code on 2006 passat 3.6*

I changed the thrust sensor (fuel pressure sensor) as dealer recommended (costed almost $500).
It was off and passed the smog test. But after two weeks, it came back.
I have no idea what should I do next. I just do not want to spend another $500 on this car. It is costly.


----------



## MLue1 (Apr 27, 2008)

You don't have the same engine but this code is not listed anywhere and seems to be a money maker for the Dealerships.

What I found is that this code is essentially caused by an air leak. It could be as simple as the gas cap o-ring leaking (spray the o-ring with WD-40 and let soak then install it if it fixes it then it is a $12 fix to replace) or as costly $$$ as a Rear Main Seal (RMS) leaking oil. Check the Air/Oil Separator (PCV), the rubber membrane inside can tear and cause an air leak as well.

Good Luck


----------



## alkla1 (Dec 16, 2014)

*12a2*

Check the oil separator (PCV) system. just sayin':laugh:


----------



## lethal6 (Feb 19, 2013)

alkla1 said:


> Check the oil separator (PCV) system. just sayin':laugh:


Check the dates of the threads...just sayin'...


----------



## MLue1 (Apr 27, 2008)

Good time to update this, it turned out to be the Rear Main Seal (RMS) which failed because of a bad Air Oil Seperator (PVC). Replacing the PCV alone did not fix the problem.


----------



## MeadowL (Apr 3, 2015)

I have the same code-P12A2 coming up on my 2006 Passat. My mechanic says it's low fuel pressure but diagnostic test hasn't been run yet. Dealership says the ignition coil needs replace as a recall for this model. I'm hoping the engine light will turn off after that repair but good to know if the light comes/stays on.


----------



## BTJaree (Feb 15, 2011)

*Cost?*

How much did it (or will it) cost to fix the rear main seal, and oil air separator?


----------



## D-Caf (Mar 22, 2009)

BTJaree said:


> How much did it (or will it) cost to fix the rear main seal, and oil air separator?


Replacing the PVC at the dealer costs around $250 (+/- $50 depending on dealer). I had it replaced at 60K as preventative, so far so good at 85K.

Rear Main Seal is a LOT more, a lot lot more. I don't remember exactly, but I think people had said over $1K in costs.


----------

