RS246.com Forum :: The World's #1 Audi R, S and RS Enthusiast Community

My much-loved, 09 plate 'C6' has had Revo Stage 1 remap since 2016. It had a recurring problem with the secondary air intake system, which was resolved by replacing one of the actuator arms. Since then I have enjoyed relatively trouble-free driving.

However, just occasionally, it will throw a fault

001170 - Secondary Air Injection System: Bank 2 P0492 - 002 - Insufficient Flow - MIL ON

I have got into the habit of using the HEX-NET to clear the fault.

However, recently, the insufficient flow fault has started to come on more frequently. And it has been joined by a new code:

008801 - Boost Pressure Control Valve (N249) P2261 - 008 - Mechanical Malfunction

I have taken it to a local independent workshop (that specialises in exotics; Porkers, Ferraris, Astons, and vintage), and they recommend using a rolling road for proper diagnostic session.

What does the forum recommend? Any quick solutions, or recommendations for rolling road facilities, or anyone think I should let Huntingdon Audi take a look.

I'd appreciate your advice.

Thank you,

They recommended a rolling road test with a known fault? That sounds like guessing. Why not just check the connector or replace the valve?

When does the 1170 fault occur? Is it after a cold start?

When does the 8801 fault occur? Is it when you put your foot down, or when you lift off?

Nick

To be fair to the garage, they said they could start replacing parts but - based on previous experiences with complex systems - they wanted to be more sure of the cause of the fault before doing work or replacing things that might not resolve the issue.

I can't discern a pattern on the 1170 fault. Perhaps two thirds are shortly (say, five minutes') after cold start. The 'freeze frame' data suggests it was triggered most recently when accelerating from stationary when cold.
RPM: 855 /min
Load: 52.9 %
Speed: 2.0 km/h
Temperature: 27.0°C
Temperature: 19.0°C
Absolute Pres.: 990.0 mbar
Voltage: 12.700 V

The 'freeze frame' data for the the 8801 is as below, and assuming I am reading it correctly looks like when lifting.
RPM: 4947 /min
Load: 7.1 %
Speed: 125.0 km/h
Temperature: 92.0°C
Temperature: 69.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 12.446 V

Again - any words of wisdom gratefully received.

Can anyone recommend a good diagnostic route, ideally an outfit with a rolling road?

Thank you in advance,

Whereabouts are you? Not sure you need a rolling road - you can log all the parameters needed on the road. I'd go to an Audi specialist who has probably been there and got the t-shirt with most faults. Try unit20 or MRC.

What I would do first is disconnect the N249 connector and slide it on and off several times, and see if that makes any difference. Sometimes works.

Then I would just replace the control valve. I don't see the point of a rolling road test. That would tell you less than you know already.

Nick

008801 - Boost Pressure Control Valve (N249) P2261 - 008 - Mechanical Malfunction

The single N249 valve controls the operation of the two Blow-Off Valves, one built into the base of each airbox, and it's well know that it gets "sticky" over time leading to both of the blow-off valves not working correctly and leaking air when they shouldn't. It's quite easy to change as it lives just under the "V10" plastic engine cover at the rear of the engine - Pt No 07L 906 270 - and visually it looks identical to this N75 valve

Wonderful - thank you for the responses.