N75 Valve

[CSS3]

Hey All,

The past week or so I have noticed my boost gauge has dramatically dropped in boost, having stages where the car is idling at 1,000 revs rather than the usual 800 / 900 rpm. When stopping at lights also seems to feel like it wants to stall, I'm getting maximum of 0.2 bar of boost.

I plugged it in today and found this fault.

01262 - Solenoid Valve for Boost Pressure Control (N75): Output Open

I immediately went to my other A3 and took the N75 valve out of it just to swap it over to see if there's a difference, plugged it back in, etc and the fault code still shows.

The drive of my car at the moment is probably the worst I've experienced whilst owning an 8L and would like to resolve this problem

I've read somewhere else that maybe a faulty / blocked fuel filter could be the cause of this problem, correct me if I'm wrong ?


Would appreciate any help.

 

[SamHendry]

Sounds like wiring problem. Check the plug that connects to the n75, the wire can break off from the pin meaning n75 won't function. It's what happened to mine.

 

[Stuart B]

obviously you cleared the fault after changing the N75?

I assume you are at about 6psi? so the N75 is not electronically connected, I know it's frowned upon but if you have an MBC laying around you could at least prove the rest of the components are okay bypassing the N75 with a manual boost controller - then it at least focuses the fault on the N75 associated connector or wiring.

With my old S3 Map when the car was started and a snowflake was on the DIS I only got about 6psi, unless it was "rebooted" (switched off and on again)