ingelstrada

A month ago I filled up with horrible gas, something called Murphy's. Didn't have much choice at the time.

Since then the car has been running like crap. Lots of bucking, inability to accelerate properly, difficulty in starting. And sometimes the "ESP fault" error accompanied with flashing CEL for a few minutes after cold start.

So I ran Techron for a couple of thousand miles and changed the fuel filter, the spark plugs, air filter and oil. 90% of the issue is is gone but I still have unpleasant behavior by the engine. I have two codes:

2 Faults Found:

008852 - Fuel Pressure Regulator Valve (N276)
P2294 - 009 - Open Circuit
Freeze Frame:
Fault Status: 00010100
Fault Priority: 4
Fault Frequency: 1
Reset counter: 40
Mileage: 264019 km
Time Indication: 0
Date: 2015.12.27
Time: 19:12:02

Freeze Frame:
RPM: 576 /min
Mass Air / Rev.: 136.3 mg/str
Temperature: 79.5°C
Pressure: 23.1 bar
Voltage: 12.65 V
Temperature: 16.5°C

008304 - Intake Manifold Tuning Valve (Bank 1)
P2070 - 006 - Stuck Open
Freeze Frame:
Fault Status: 00100001
Fault Priority: 2
Fault Frequency: 1
Reset counter: 40
Mileage: 264019 km
Time Indication: 0
Date: 2015.12.27
Time: 19:12:18

Freeze Frame:
RPM: 768 /min
Mass Air / Rev.: 174.4 mg/str
Temperature: 75.0°C
Idle
Absolute Pres.: 563.9 mbar
Speed: 3.0 km/h


Readiness: 0110 0101


The internet wisdom about "Intake Manifold Tuning Valve (Bank 1) P2070 - 006 - Stuck Open" is that it's a vacuum line that is cracked. Mine wasn't cracked but was brittle and broke while I was checking it so ended up replacing with a vacuum hose as found on this forum. The code remained.

I'm not sure if these two codes are related to each other (one causes the other) and what the reasons would be?

ingelstrada

2008 A6 C6 Quattro, 164,000 miles on the clock, 3.2l engine with 10k OCI interval.

ingelstrada

And now the car has developed the dreaded diesel sound of the timing chain tensioner issue on the driver side at cold startup that gets progressively louder, then stops, runs quiet and then gets progressively louder for about 3-4 minutes.

Why do these things always happen in winter when I need my Quattro most?

iaflyer

It's possible that it's the MAF sensor, (Mass Air Flow), sometimes what might be a vacuum line problem is actually that. I don't think they are hard to replace.

ingelstrada

The car is currently in a repair shop going through diagnosis. Will update this thread once the issue is identified and fixed.

ingelstrada

For the
008852 - Fuel Pressure Regulator Valve (N276)
P2294 - 009 - Open Circuit

error, the shop has tracked it down to the ECU and recommends ECU replacement.

I am quite dubious of the ECU causing an open circuit error but I could be wrong.

audi bug

What type of repair shop are you using?
Is it familiar with VW and Audi cars?
Did it tell you why ECU is suspect?

My bet is the high pressure fuel pump rather than ECU causing P2294.
Google and review P2294 for VW and Audi.

ingelstrada

They have a reputation that they are. Indianapolis Auto Repair for Audi, BMW, Land Rover, Lexus, Mercedes Benz, Porsche, Volkswagen, Volvo, Saab :: Euro Motorworks for those who live near Indianapolis.

They arrived to that conclusion after eliminating everything else according to the service guy I spoke to.

ingelstrada

After about a month in the shop, the problems were finally diagnosed and fixed.

The P2294 was indeed the high pressure fuel pump. Not the ECU as they diagnosed at first.

The P2070 was caused not by a vacuum leak but a bad intake valve solenoid.

audi bug

Thanks for updating the result.