Golf Mk5 1.9 TDI EML light stays on with new EGR valve

[AndyGolf]

Any help please ...

My car : Golf 1.9 TDI 57 plate Auto Engine Code BXE

Problem : Amber EML light, if clears comes back on.
VCDS reports Motor for Intake Manifold Flap (V157): Malfunction

and cheap from ebay Elm connecter reports two errors -
1) P2100 Throttle Motor Circuit open
2) P2102 Throttle Motor circuit low.

WITH NEW EGR fitted myself !

And of course I cant get the car through MOT with this problem !!!

History:
Driving on motoway, amber EML came on (before this car was a bit lumpy driving uphill on motorway)
AA did a scan and said I needed a new Throttle body.
I changed throttle body myself, A pierberg sourced from Murrays Direct near London.
Car now drives alot better.
Amber EML light STILL on.
Resetting Amber EML, the light never comes back on when driving (good).
When next restarting engine, Amber EML light comes on.

The errors stored are consistently as listed above.

I've read fuse 8 or 24 can be blown, checked them and they are ok.


Some underbonnet tests I did yesterday:

Took off intake hose, i could see the flap is in open position. I guess thats why the car still runs.
I did some testing yesterday with a multimeter, and found of the 4 pin connector that only 3.22 volts
is being read into it.
When i test I think the coolent sensor nearby , it has 4.95v feed in.

So it seems the voltage going to the EGR connector is not high enough.

Not sure if any relays can be checked or are used or where/what to try next withou giving car over
to maybe mega expensive dealership.

If someone cracks this, free beer will be posted !

[Oscar011]

Re take off the intake hose, look at the inlet motor valve (anti shudder valve). Get someone to turn the ignition on then off and so on whilst you look at the anti shudder valve. The anti shudder valve should close for a few seconds then reopen when you turn the ignition back off. If this does not happen I would suspect a faulty unit or an electrical fault. But this should give you an idea of what to do next.

[AndyGolf]

thanks for the reply,

the valve flap does not move,just stays open all the time.
I think its meant to shut when starting or turning off engine to help stop the engine juddering around.
Not sure how/when the butterfly flap gets adjusted during driving.

Anyhow, it doesn't move, its brand new !

[stevieturbo]

If you dont know what the wires are doing....no point sticking a voltmeter into them.

So what is VCDS reporting now ? Ignore anything from a generic OBD reader, they generally mislead.

Is the EGR actually functioning ?

[AndyGolf]

Well testing the wires will at least tell me if the wiring is dead or not.
I remember AA guy saying it should be fed with 5v, im only getting 3.2v.

The EGR valve does not work at all, it normally makes a clicking sound when you switch on/off ignition.
It was also tested with VCDS , it has an off/on software button, pressing this test in the software and EGR made no clicking, its not working.

VCDS reports error V157, written up here -
http://wiki.ross-tech.com/wiki/index.php/19559/P31...
(cant see how to paste link, new to website !)

[stevieturbo]

AndyGolf said:

Well testing the wires will at least tell me if the wiring is dead or not.
I remember AA guy saying it should be fed with 5v, im only getting 3.2v.

The EGR valve does not work at all, it normally makes a clicking sound when you switch on/off ignition.
It was also tested with VCDS , it has an off/on software button, pressing this test in the software and EGR made no clicking, its not working.

VCDS reports error V157, written up here -
http://wiki.ross-tech.com/wiki/index.php/19559/P31...
(cant see how to paste link, new to website !)

And again, unless you know exactly what you're doing, no sense sticking a voltmeter into things. Him saying something vague like that is meaningless.

And you do realise the intake manifold flap and EGR may be separate items ? So you changed the EGR valve when there was a different fault code ?

And the EGR valve on the engine may be a mechanical valve operated by vacuum. It may not be directly controlled electronically. Have you tested all those aspects ? ( Even though it seems unclear that the EGR is actually the problem here )

Edited by stevieturbo on Sunday 3rd March 20:57