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Seat Leon 1600 16v BCB 2004 - EGR flow fault, code P0402 #

Posted by Andrew West on July 23, 2009, 11:16 pm

Year of Manufacture *: 2004
Engine Code or Type *: BCB
( Optional ) ECU Type: Marelli 4mv
( Optional ) Scanner used: Autologic

Hello all,
I have the above vehicle in from another garage who has replaced the egr valve twice, first one non genuine, then a genuine one, because of fault code P0402 EGR FLOW TOO HIGH(EXCESSIVE) & the fault still reappears. I have checked for leaks & found none, the EGR valve appears to operate correctly when actuated, but when trying to perform EGR flow adaptions the egr doesn't operate & fails the adaption test.I have removed the EGR valve & checked it & cleaned the throttle body & reset adaptions etc.
I should be able to find what's going on, because I currently have a VW Golf 1600 16v AZD engine code with the same management system , which I have been able to scope to compare with the Seat.
I think that there must be a fault with the control module, but would like some advice/comments on the waveforms.

Blue trace = EGR position.
Red trace = Wideband sensor
Green Trace = TPS
Yellow trace MAP sensor

The first waveform is the VW Golf (which has another fault, but performs the EGR adaption/test ok with a pressure difference of 85 mbar).
The second waveform is the Seat, where the EGR position doesn't change (the waveform isn't quite positioned correctly, but on subsequent tests it definitely doesn't alter position).The lambda reaction is a bit different & slower, but everything else appears ok.

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Kind regards,Andrew

Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault

Posted by John Ritchie <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2638' width='330' height='300' border=0 style='border:none;'> on July 24, 2009, 10:11 pm, in reply to "Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault"

Hi Andrew

Did you notice what the egr duty cycle was between the 2 cars ? , has this model got a DPFE sensor ?
Out of interest looking from the scope trace did your foot touch the acclerator about 7.7s as there was a increase in tp volts and drop in vac.

Regards
JR
P.S Did Lawrence have any thoughts on this?

Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault

Posted by Andrew West <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5350' width='330' height='300' border=0 style='border:none;'> on July 25, 2009, 6:34 pm, in reply to "Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault"
Andrew West

Hello John,
How did you know that I have spoken to Lawrence?
Is the DPFE sensor the one on the back of the engine on what looks like the crankcase breather.Autodata doesn't show anything there & there isn't one fitted on the VW.
My foot didn't touch the pedal at 7.7 ms & the same increase in tp volts & drop in vac happened on both vehicles, but not as much on the top waveform. Lawrence thought that it was an odd fault, suggested rechecking for blockages or leaks & didn't like to suggest an ecu fault.He also said that the management system was looking for a difference in pressure before it operated the EGR valve ,but I would have thought that it was looking at the presure difference when it actually operated the EGR valve.Now that you have mentioned about what could be a DPFE sensor, I should think that it is most likely the cause of the fault.
Thank you very much for your reply.I will test the sensor on Monday, as I have got to go in now to get changed ready to go out & I'll let you know what happens.
Kind regards,Andrew

Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault

Posted by Sean Mc Gettigan <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5291' width='330' height='300' border=0 style='border:none;'> on July 25, 2009, 8:20 pm, in reply to "Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault"
Sean McGettigan

Did you see this Andrew?
http://members5.boardhost.com/ukautotalk4/msg/1189367851.html
Sean

Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault

Posted by Andrew West <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5350' width='330' height='300' border=0 style='border:none;'> on July 26, 2009, 12:09 pm, in reply to "Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault"

Hello Sean,
Thanks for your reply. I have read through the post & tried reading channel 0 in engine adaptions, with the Autologic & Autodiagnos, but can't seem to find channel 0. If I try resetting engine adaptions using autologic, it asks for a engine access code & a vehicle access code.
I think I must need to enter a login code, unless you can advise me otherwise.
Regards,Andrew.

Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault

Posted by David Davies <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5218' width='330' height='300' border=0 style='border:none;'> on July 26, 2009, 1:26 pm, in reply to "Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault"

Andrew,
As far as I know there is no channel 0.There are 100 channels from 00 to 99.Did you mean channel 00?

Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault

Posted by John Ritchie <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2638' width='330' height='300' border=0 style='border:none;'> on July 26, 2009, 7:57 pm, in reply to "Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault"
John Ritchie

Hi Andrew , just assumed having AL you would have phoned Lawrence , interesting fault though

Regards
JR

Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault

Posted by Sean Mc Gettigan <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5291' width='330' height='300' border=0 style='border:none;'> on July 27, 2009, 9:08 am, in reply to "Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault"
Sean McGettigan

Hi Andrew,
First is the AL in full or Ltd diagnostics for this system?
Have you removed the EGR sandwich plate under the throttle body and cleaned it?
Have you tried the reset under basic settings as opposed to adaptions?
I dont remember needing a login code for this ever but if you do Lawrence will supply it.
Hth Sean

Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault

Posted by Andrew West <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5350' width='330' height='300' border=0 style='border:none;'> on July 27, 2009, 3:24 pm, in reply to "Re: Seat Leon 1600 16v BCB engine code 2004 year EGR flow fault"
Andrew West

Hello Sean,
Thanks for your reply.
I couldn't do the basic adaptions in channel zero, because it isn't supported by this unit. There is no EGR sandwich plate, but I did remove the throttle body & clean it more thoroughly. I have got full diagnostic capability on the Autologic(as far as I know). I removed the ecu & coded it to the vw golf that I have here & it performed the egr adaption ok, so there must be something that I am missing somewhere. The customer is picking the vehicle up soon & I can't afford to spend any more time on it, although I would like to get it sorted. The only difference I can see between the two vehicles apart from the vacuum difference that I already mentioned, is that the Seat has got a heated engine breather(not pressure sensor as I thought it could have been when somebody mentioned the possibility of a DPFE)& the breather system also is piped from the filler cap into the manifold.I have tried blanking them off etc, but still can't get it to pass the EGR flow test.
Anyway, thanks for everyone's help, there is a chance that I may be able to look at it again & if it gets fixed i will post it.
Regards,Andrew

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