Exhaust System Fault - 2008 Passat TDI

[sporran]

Hi, the Exhaust System Fault light ( Orange Engine Block Symbol) has appeared on the dash of my 08 TDI (125 kw) Passat and I am after some advice on how to approach it.

I spoke with the Service Department of the VW Dealership that service the car and the guy suggested that It could be a problem with the Particulate Filter as I have been doing a lot of short travel distances in recent times. He suggested that I take the car on to the freeway on a trip that will take it over 80 km/hr, and this may clear any build up in of soot that may be causing the fault.

Having read the manual this advice appears to be at odds with what is suggested, which is to take the car to the nearest Service Department.

Any advice would be appreciated, as I don't want to cause any damage to the car if the advice from the guy from the Service Department's turns out to be incorrect.

[Greg Roles]

That light can come on for many reasons, but yes, the most likely is going to be a failed DPF regeneration. This is when it is over 40% full. Absolutely no harm in taking it for a 30 min highway drive, give it a chance to do a proper regen. If it continues to fail to regen, eventually the coil light will come on as well ( 60% full ), and the car will try and regen every time you start it. Only at this point would it become necessary to consider going to a dealer. At 80% full the car goes into limp, and you will have to have it towed to a dealer.

Go give it a 100kph drive.

[sporran]

Thanks Greg will follow your advice and if that fixes it.

[PHA]

I realise this is an old thread, but I've just had the same problem on my MY07 103TDI which has now covered 77.000km. The car has gone into limp mode with limited power and gear changes that remind me of a 1960's powerglide transmission.

Being a 103 it doesn't have a DPF. I guess it's off to the dealer's tomorrow. Does anyone have any ideas as to what the trouble may be?

Postscript: Took the car into the dealers but apparently their tech has called in sick for the rest of the week. They reset the computer, cleared the codes and took copious notes. It got about 1km before the light came on again and back to limp mode .. Looks like the car gets parked until next week then they can have another look at it.

Post-Postscript: a real turn up for the books. It took the dealer a while to figure out, but it turned out that a rodent has had a meal of the wiring harness just below the air box. It managed to really enjoy the wire controlling turbo boost among others. Guess I can't blame VW for that unless they need to use less tasty insulation!

All fixed and I'm smiling again although $360 lighter.

Maybe, just maybe, this might even solve the problem I've had since new of the car missing when driving off cold or after parked for a couple of hours???