Audi 2.0 TDi - V157 Motor for Manifold Intake Flap - Intermittent Fault P3103

[tinochelli]

Hi All,

Hoping to get a bit of help as my local Audi Dealer is not showing much certainty in how to resolve the V157 fault. They have said that it could be the Throttle Body (Controller Lid), EGR or the intake manifold or possibly a sensor issue.


When I turn off the ignition I do notice more of a judder in the engine sometimes.

This is what i have done so far:

-Removed the Throttle body and cleaned it - flap is intact and teeth feel like they have tension all the way to closed. Vale is open by default.
-Removed EGR and cleaned this also. Re-tested and EML remained on most of the time but occasionally turned off.

Just recently the turbo has now started to be intermittent with no obvious pattern Sometimes its just not there but could appear in 2nd or in 5th. But if/when the turbo does kick in if i keep increasing speed through the gears the turbo seems to stay until i slow down. Almost like a pressure issue?? But this issue has only come after the initial EML - not at the same time.

I bought a 2nd hand throttle body and replaced it yesterday (controller lid as audi dealer refers to it) and retested. The turbo now works through all the gears but then i remembered that i forgot to connect the electrical connection back onto the throttle body...arrgh!! As soon as i reconnected it the turbo issue returned. I am wondering if this is actually a sensor/electrical type issue and the mechanical parts for the manifold are actually ok??

I am really hoping for some advice that i can do to help find the actual fault and not just replace parts that are related.

Any advice would be really appreciated.

Thanks

Franco

 

[Johnny Bravo]

That throttle body is actually called anti-shudder valve (ASV). It helps the engine to turn off smoothly. The flap cuts the air to the cylinders and reduces the judder.
The flap is moved by some plastic gears which tend to brake and cannot be replaced.
When the ASV gives in usually some fuses will also blow. Give them a check too. There are some in the engine bay, next to the battery and some behind the dashboard.