Yaemish

My 2012 Q7 has been getting intermittent "Cylinder 2 Pressure Too Low/High" codes for the past month and they have been becoming more frequent. I had them occasionally last summer, nothing for the fall and winter, and they began to return when the weather warmed.

I am under warranty, the closest dealer is about an hour away, so it would be cheapest and easiest for me to just replace the problematic glow plug with sensor. There is no sense in driving it there for an appointment and then have to drive there at a later date.

What I am concerned about is that the pressure problem may actually have something to do with the high pressure fuel pump. Now it may just be part of my paranoia, but I feel like I can hear a bit of a whine inside the vehicle and I fear that it is the fuel pump. When I get some time this week, I will hook up the OBDeleven and run the function to turn the fuel pump on in order to determine if the noise I hear is the same.

When those pumps are on their way out, has anyone seen them cause the "Cylinder Pressure Low/High" codes? I'd like to be proactive about this type of problem, even if there is a warranty.

Thanks!

'10Q7TDI_Prestige'

I drive 3.5 hrs one-way to get to an Audi dealer. They give me a loaner car to drive (set it up in advance), and usually have the car for a few days to a week. This last time was 90+ days while waiting on a part from Germany, and yeah, I thought that trip was just a silly sensor going out also...sensor was downstream of the real issue. Use your warranty; you might be surprised what gets replaced. Also, you should be checking your car for leaks that are likely accumulating residue in the belly splash pans...you can get those fixed under warranty and check for other TSBs/known issues applicable to your year model.

-Wes-

One year later....

Any update on what this turned out to be and the actions you took to resolve it?

I am getting intermittent P03A5 codes, "Cylinder 2 Pressure Too High." It always (and only) happens after I am driving it on the highway at high speeds for a sustained period of time, then I drop off the throttle for some reason (such as taking an exit or slowing for traffic ahead of me). Sometimes I will go thousands of miles without a recurrence, and sometimes less than a hundred. Doesn't happen in local stop/go. Doesn't seem to happen first thing in the morning.

I notice no issues with the engine operation at all during these times.

-Wes-

Just an update a couple years later.... No change with my Q7. I still get the intermittent P03A5 code, and I am 100% unsure of what is causing it. I thought, perhaps, that it could be related to a coolant leak I found inside the EGR cooler. However, after definitively resolving that issue, there was no change to the behavior of the P03A5 frequency. I am just going to take the "wait and see" approach for now. Aside from the persistent engine light on the dash, the vehicle seems to be running wonderfully.

'10Q7TDI_Prestige'

Here's a related thread: skip to the end recommended, although lots of good info in it: Spoiler alert, it ended up being the custom tune/semi-custom tune installed.

https://forums.tdiclub.com/index.php...4/post-5851741

-Wes-

Interesting, indeed. Thanks for that. Very possibly a tune issue, though I ran the car for several thousand miles and a couple of months before the code triggered for the first time, if I recall correctly. I'm just happy that I have zero other issues aside from the code triggering, which is unlike the poster(s) in that thread. Since I'm just about to head off on the annual Ohio trek (a journey the Q7 will not be taking this time around), this will need to remain a problem for another time.