# Phaeton 3.0TDi 2005 'Engine workshop fault' or 'Exhaust workshop fault' and flashing coil



## Tex Gore (Nov 27, 2009)

So, the latest problem with the Phaeton is EITHER 'Engine workshop fault' or 'Exhaust workshop fault'. The latter has been on for a few days, however yesterday was accompanied by a flashing coil light and the car lost almost all power.

So I took it to a diesel specialist as the VW Dealers around here are just awful, and using a Delphi system he read a single fault code which pointed to the DPF pressure. He suggested a regeneration, however there was no option to do this.

When I start the vehicle the warning lights remain off for a few seconds and the car drives normally, then on they come (either Engine or Exhaust workshop fault, always now accompanied by the dreaded flashing coil).

I took it out this evening and maintained 3000RPM or above for about 30minutes (with the odd stop for traffic lights) but this hasn't made any difference.

I am reluctant to spend any more money on this car as, owing to it's unreliability and expense it's going back in a week, however I cannot return it with warning lights on. Long story. I am NOT selling it privately - not trying to fool anyone.

Can anyone suggest anything I haven't tried please? Is it worth just sitting on the drive with it revving at 4000 or so as with a regeneration? I understand that also involved increased diesel into the exhausts though. 

Any thoughts greatly appreciated,

Thanks in advance

TG


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## Prince Ludwig (Mar 24, 2007)

This might help if you can get hold of a vag-com.

Harry


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## n968412L (Apr 23, 2009)

It might... but this bit is a little scary:

*If the Particle Filter Load is above 68g the Particle Filter needs to be replaced since the car may burn down when regenerating*. 

I think I'd want to know how to check that loading first!!

Does anyone have any practical experience of doing this?

Good luck!

M


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## Prince Ludwig (Mar 24, 2007)

> I think I'd want to know how to check that loading first!!


That's why it gives you the MVB to check first...

Harry


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## n968412L (Apr 23, 2009)

Prince Ludwig said:


> That's why it gives you the MVB to check first...
> 
> Harry


I read it too early in the morning... didn't think to scroll up... RTFM!

Regards

M


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## choccy01 (Mar 25, 2010)

*exhaust workshop light and flashing coil*

hi,
I'm having very simuler problems, have had the exhaust workshop light on for a couple of months(suspect air filter needs changing). last night during 200 mile run flashing coil light came on, lost a little power, drove last 50 miles at 60mph, cars due a service, any ideas???
do not have VAG 
thanks
terry


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## Prince Ludwig (Mar 24, 2007)

Sounds like the exhaust warning was caused by increasing back pressure from the DPF and since nothing was done about it it's now blocked and can't regenerate. You might be able to get away with an emergency regeneration as detailed in the link above but if not budget £1000+ for a new DPF at a main dealer.

Harry


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## jkuisma (Nov 23, 2009)

Hopefully it is just the DPF pressure differential sensor gone bad. It is very common for the sensor to fail. It is relatively cheap (about 150 euros) but a pain to replace. Can be done on a lift in about an hour - assuming one has gynecologist's hands.

This should be pretty straightforward to diagnose with VCDS or dealer's VAS. Implausible signal/reading from pressure sensor indicates it is the cause of problems. Regeneration fault is a sign of something more severe. I would trust the dealer on this. They should rule out the sensor before suggesting replacement of the DPF itself.

Jouko


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## snapdragon (Aug 8, 2006)

My DPF blocked and caused the turbo gasket between left and right side to blow because I gingerly used it for another 40 miles over 2 days instead of leaving it as the dealer. The power was down more and more and the turbo gasket blew and made a whistling noise and became too hot.

It needed new turbocharger and had the wretched DPF hollowed out which can be done by removing it and poking the honeycomb out with a metal rod (similar to crunchy bar packed with soot). A very messy job, wetting it helps keep the soot from going everywhere.

The ECU was then reflashed by someone I found via google to eliminate the DPF daemons. Peformance was better than ever with the DPF gone and new turbo.

Total cost to me was about £1200, vs £3200 at the dealership.


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## choccy01 (Mar 25, 2010)

im booked in to my local vw independent dealer next monday, will keep you all updated, thanks for the info


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## choccy01 (Mar 25, 2010)

*exhaust workshop light and flashing coil*

hi all,
finally out of garage after a week, needed g450 exhaust pressure sensor and j338 throttle flap, 
£750 to get it all sorted at independent VW dealer, only money I've spent in 4 years, might be time to get rid?
cheers
terry


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