…. 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… .

 

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.

 

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

 

12a2

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

 

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

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

 

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.

 

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.

 

Cost?

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

 

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.

 

i heard if one of the clips on your fuel line breaks when changing the fuel filter the entire fuel line will thrn meed replaced. try removing the lines to the fuel filter and checking if they click when reconnecting them.... maybe one of the tabs were broken and its no longer getting the same pressure...