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Audi A2 1.4 AMF 2005 - Poor performance, code 17964 - Fixed #

Posted by Mark Robins on December 16, 2010, 1:02 pm

Year of Manufacture *: 2005
Engine Size and Code *: AMF 1.4cc
( Optional ) Scanner Used: Autocom
( Optional) Fault Codes: 17964 Charge pressure control negative deviation

Hi all,

Boost pressure is varying up and down, some times making 1.2 bar. So far we have smoked the intake system found a small leak on the inter-cooler (there is a small spigot I think for draining on the bottom) which we repaired. Scoped injector current right through rev range (it feels like a miss-fire on occasions)can see no problems there. Checked boost control solenoid and pipework OK, disconnected the waste gate actuator (not variable vane) and problem still exists. We've removed the turbo for examination turbine blades all OK, but have .5mm side play in shaft does anyone know if this is excessive and more to the point will cause this problem?

Mark

Re: Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #

Posted by Mark Carter <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on December 17, 2010, 7:22 pm, in reply to "Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #"
Mark Carter

Hi Mark,

I have;

17964/P1556/005462

1 17964/P1556 - Charge Pressure Control: Negative Deviation
1.1 Possible Symptoms
1.2 Possible Causes
1.3 Possible Solutions

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

This is from Ross-Tech Wiki HTH

Regards Mark

Modern cars, Its all wizardry and witchcraft

Re: Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #

Posted by roy ritchie <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT5115' width='330' height='300' border=0 style='border:none;'> on December 19, 2010, 11:37 am, in reply to "Re: Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #"

Part Blockage in exhaust,Seen a few of these with same fault.

Re: Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #

Posted by Mark Robins <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on December 19, 2010, 11:33 pm, in reply to "Re: Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #"

Cheers Roy,

Sounds very plausible I'll inspect it in the morning.

Mark.

Re: Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #

Posted by Chris Angus on December 20, 2010, 7:11 pm, in reply to "Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #"
Message modified by board administrator December 21, 2010, 3:35 pm

Sounds like a boost leak to me.
I have no experience with Autocom, can you log the data, desired and actual boost and duty cycle?
I would recommend vag com, so much easier for this test.

Aslo the smoke test is no good for finding boost leaks, just not enough pressure. We have adapters made up to fit the inlet side of the turbo using a tyre valve and tyre inflater we can pressurize it as high as we need, then just listen. I know access can be tight and not always practical, but there's usually a way.

Hope this might help.

Chris

Re: Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #

Posted by Mark Robins <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on December 22, 2010, 9:19 am, in reply to "Re: Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #"

Thanks for the input guys, checked exhaust silencer and cat all OK, techi's from turbo company say that .5mm in turbine shaft is to much but I'm not convinced that this is my problem. Chris I have VAGCOM and I will double check inlet trunking, but at the moment I have the turbo off, will update when I have more news.

Mark

Re: Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #

Posted by Mark Robins <iframe src='https://members.boardhost.com/ukautotalk8/info/user=UKAT1448' width='330' height='300' border=0 style='border:none;'> on December 23, 2010, 8:41 am, in reply to "Re: Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #"
Mark Robins

Rechecked the inlet trunking pressurized it to 10 psi definitely no leaks (can visually examine all of it as well), turns out .5mm play is acceptable on the turbine shaft side to side play, cut open cat and rear silencer; all OK, once reassembled I'm going to concentrate more on the fueling side I'm convinced this miss-fire feel has something to do with it.

Mark

Fixed #

Posted by Mark Robins on December 24, 2010, 6:38 pm, in reply to "Audi A2 1.4 AMF 2005 - Poor performance, code 17964 #"
Message modified by board administrator February 11, 2011, 2:18 pm

Hia all,

What a bummer! Checked fuel supply by fitting vac gauge to inlet side of pump and had a massive vac reading indicating an obvious restricted fuel supply line, turns out the fuel filter was blocked; we never went down this avenue because the customer said the vehicle was fully serviced two months previous, just goes to show you never assume anything, obviously no fuel equals low boost. Changed fuel filter everything OK, we logged eight hours on this, I feel like spitting!

Mark

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