hope some one can help i have a 1.4 tdi 04 plate and the eml has come on and i have lost power its as if the turbo isent working but if you turn the engine off and re start it all is ok untill it starts again have had it scaned and code 17964 charge presure control intermittent any one got a clue

taken from the Ross Tech Wiki, turbo vanes sticking was a suggestion i saw on another forum

17964/P1556 - Charge Pressure Control: Negative Deviation

Possible Symptoms

Reduced power output

Limp mode

Possible Causes

Boost Pressure too Low

Hoses/Pipes incorrect connected, disconnected or leaking

Charger Pressure Control defective

VNT (variable nozzle turbo): nozzles stuck

Solenoid Valve for Boost Pressure Control (N75) defective

Possible Solutions

Check Hoses/Pipes to/between Components

Check Solenoid Valve for Boost Pressure Control (N75)

Check / Clean / Replace Charge Pressure Control

Check / Clean mechanism for variable nozzles

I too have a 1.4TDI 04 plate with this problem. Power will suddenly go when engine is under load, eg when going up hill, or moderate to hard acceleration on flat. Restarting engine cures problem for a few minutes, but it inevitably returns. Local independent garage has come up with fault code 17964/P1556. Have had airflow meter and MAP sensor replaced without success. Did any of the suggestions above work? Is there anything else that can be tried? The EGR light comes on sometimes when this happens, but not necessarily, seems a bit random. It doesn't seem to be a problem with any of the hoses. Any thoughts appreciated.

jme

Many moons ago, I had an MG Montego, Turbo which had a similar problem. The Rover bods tried in vain to get it fixed but failed. (It lost power as you tried to get the turbo spinning up).

They suggested that one of the many hoses had started to leak and it was trial and error to find it. This, after quite a few hours trained techie-messing (and expense).

I then set about searching for myself, run the engine to hunt for leaking hoses... Put my hand round the first, biggest hose in front of me, aside (from rad hoses) and as my hand gripped, my finger went straight into a hole the size of a 5p coin!

Took the pipe of and to a local motor factor who sold me a length of similar bore hose, without the fancy bends of the factory job, I fitted it and the problem never re-occured!

How the pro's missed it, I will never know but it was right there. Not suggesting it will be the same for you but check the blower hoses out first as simple things get easily overlooked by highly trained egg-heads as they ALWAYS suspect the worse.

I too have a 1.4TDI 04 plate with this problem. Power will suddenly go when engine is under load, eg when going up hill, or moderate to hard acceleration on flat. Restarting engine cures problem for a few minutes, but it inevitably returns. Local independent garage has come up with fault code 17964/P1556. Have had airflow meter and MAP sensor replaced without success. Did any of the suggestions above work? Is there anything else that can be tried? The EGR light comes on sometimes when this happens, but not necessarily, seems a bit random. It doesn't seem to be a problem with any of the hoses. Any thoughts appreciated.

jme

hope some one can help i have a 1.4 tdi 04 plate and the eml has come on and i have lost power its as if the turbo isent working but if you turn the engine off and re start it all is ok untill it starts again have had it scaned and code 17964 charge presure control intermittent any one got a clue

have u managed to find the problem for this error ??

I have a 1.4 TDI AMF Engine that's doing the same

any ideas ?

thanks