Hey guys,

First off I know there is a similar thread to this but my engine code and type of problem is a bit different so if its better to add it onto the old thread please let me know and Ill do so. Im new here so still figuring it out, but still know that there is fantastic expertise here to draw on.

Basically I have a 2004 VW Passat 1.9 TDI PD with engine code AVB. It recently went into a garage to get the DM flywheel and clutch replaced as the flywheel basically just burst itself and damaged itself. Its the first thing to ever go on the car after some 250,000 kms so I couldnt complain but I do look after it well!

Anyways, after using it for a few days I noticed the Engine Warning Light was continuously lit and my engine felt like it had a dead turbo. I connected up the VCDS by Ross-tech and found the fault was:

17964 - Charge Pressure Control : Negative Deviation

P1556 - 35-10 - - - Intermittent

There is one other problem this appears to be causing for me which doesnt appear in any of the other posts I read in relation to this fault code. When I start the engine and start to move with the engine idling (e.g. reversing back down a hill) the brake pedal is very heavy - i.e. like it is not getting any servo assistance whatsoever - I have to pretty much stand on it. If i give the engine a bit of boot the pedal is like normal once again.

I did do a 1800RPM in third gear to red-line with the VAGCOM logging. I cant seem to upload a file here but it basically shows actual boost way below expected boost when viewed in an excel sheet. Anyways, my plan of attack to isolate the problem is as follows;

1. Check all the Vacuum hoses

2. Check vacuum in pipe to turbo actuator

3. Check movement of actuator arm at turbo

4. N75 valve check

Im handy with cars and have even change a timing belt or two but I'd really like to get this fixed as soon as I can. So basically my two queries are,

a) Is there any further items I should immediately add to the above list?

b) Is the issue with the brakes connected to the loss in power and if so does it indicate what the problem may be?

Im just not in a position where I can borrow any wastegate valve or the likes to tease this problem out part by part, and my hobby shop is a few hundred miles away. Id really appreciate any advice any of you guys could offer me on this.

HTH

Ron

PS I have the excel sheet for exp/act boost, RPM vs Mark if anyone wants to take a look i can PM it.

Edited by brianthnach on 23/11/2010 at 00:29