P0401

Slideways

Hey guys, have a p0401 fault code on a 2006 1.9tdi MkV golf

Pulled the egr valve off and it was pretty cruddy, it also had one bolt left loose. Cleaned it all up and checked that it wasn't stuck. Checked the vacuum pipe to the unit on the bulkhead, it doesn't appear to have any splits in it

Before



After



Where to next? I'll bring a vacuum pump home from work when I get back in a weeks time and check that it's moving. Any other suggestions? Car is running like a clock apart from that. I only bought it a fortnight ago with the engine light already on

Slideways

Anyone??

shietpilot

The ECU is complaining about lack of EGR flow. That means that either the valve isn't opening properly or that the "flow" detection isn't working which I highly doubt because it uses manifold pressure sensors and the ECU isn't complaining about anything else. I guess the next thing to do is to get a vacuum pump and see if the valve is actually able to open fully.

Slideways

Cheers for that. I though it might have used the maf sensor to work out that the egr was opening. I'll try the vacuum pump and see where I stand..

Slideways

Just an update. I got a vacuum pump and hooked it up to the valve and it wouldn't hold a vacuum at all no matter how fast I pumped the plunger.

Had a valve shipped from the uk, worked out at AU$96. Fitted it yesterday and so far so good

shietpilot

Good job Hopefully it stays like that now!