Emissions Garage! warning message

[yesican]

Hi experts and others
I posted earlier when I was unable to remove my inlet manifold. Now I have progressed but still have a warning light and message. I have reassembled after cleaning inlet manifold EGR valve and manifold flap. The car is a Sep 2006 Golf GT TDI with BKD engine.
I have been given conflicting advice. The amber symbol described in the user manual as, “Exhaust gas warning lamp” is on all the time and each time the ignition is turned on “Emissions Garage!” is displayed for a few seconds. The car seems to be running normally. One reliable garage man has told me that after working on the problem the light will stay on until reset and I need to let the car have several periods of use before the sensors will decide if the problem has gone away. So I should drive the car then bring the car in to have the fault warning reset, and hope the light does not come on again. Another professional, associated with diagnostics, told me that the fault warning only needs resetting with safety items like airbags, and that in the case of engine matters, if the fault disappears the light goes out. Also he said that if I disconnect the battery, then reconnect, memory of this sort of fault would be wiped and so if the warning comes on before even starting the engine that suggests an electrical problem. Can anyone with knowledge or personal experience comment?

[Crasher]

What is the fault code number?

[yesican]

P0401 Exhaust gas recirculation flow: insufficient detected. This was done for me by a non VW specialist garage, but they seem like good guys!

[Vikingraider]

Could be one of a few things. Might be the intake manifold flap failing and not closing when required by the egr, might be a split or loose vacuum hose to the egr, might be the fuse for the inlet manifold flap, might be the vacuum control box faulty.

[yesican]

Thanks, Vikingraider, for your suggestions. If it was the intake manifold flap not shutting,
that would be when the ignition switch is turned off. So if the battery is disconnected for a few minutes, then reconnected turning the ignition switch on should not result in getting the warning and message, unless the fault is stored and only disappears when it is reset by a vcds device. This is something I am hoping to find out. I will re-check the vacuum hose but it looked ok. The user manual does not list a fuse for the inlet manifold flap, but discreetly refers to other fuses only changeable by a qualified dealership, and does not reveal their location. Can you tell me more? If the vacuum control box was faulty would I not get other fault codes? I only got the one.

[Vikingraider]

The inlet manifold flap (IMF) serves 2 purposes. It closes fully to stall the engine when you turn off the ignition. It also closes partly when the ECU requests EGR function to cause a vacuum through the EGR system. Without this vacuum there'd be insufficient EGR flow, so if the teeth are breaking or sticking on the IMF mechanism then it won't pull enough EGR and will throw a fault. The stored fault code will remain until cleared by diagnostics.

The fuse in the engine compartment also controls the aircon fans. I can't recall which one it is although on my Altea when I had this fault it wasn't blown anyway. You might try fuse numbers 5, 8, 22, and 24 as they seem to ring a bell for some reason. The fusebox is on top of the battery or over there somewhere.

If there's a fault in the vacuum box (I've known it once before) then it might only affect certain functions. EGR is one of them.