Exhaust Gas Warning Lamp

[gregozedobe]

What is it ? The yellow pictogram outline of an engine that stays lit up all the time (if it is continually flashing that indicates a different error).

What does it mean ? According to my owner's manual it means there is someting wrong with the "quality" of the exhaust gases.

Other symptoms ? On mine it ran really roughly just after starting once. It also seemed less torquey from 1,400 to 1,800rpm, at 1,800rpm it was a bit like a light switch had been flicked "ON" and away it went with normal power at those revs and higher. The DPF light (dots in a mffler diagram) did not light up at any time.

What was the fix ? My dealer replaced a faulty exhaust pressure sensor and forced a DPF regeneration (under warranty).

Did it fix it ? Seems to have (time will tell)

My engine is a late Nov 2006 build BPC 174hp 5 cyl R5 TDI with a DPF. It had done 53,000Km of mostly highway driving.


Has this happened to anyone else ?

[Preen59]

Bad sensor upsetting the mixture/boost at low RPM??

Love to hear what Transporter has to say..

[gregozedobe]

Bad sensor upsetting the mixture/boost at low RPM??

I'd agree if it was the O2 sensor (lambda probe) that was replaced, but it was definitely documented as an "exhaust pressure sensor" on the job sheet they gave me. But AFAIK these pressure sensors are only used to decide whether a DPF regeneration is needed yet or not (and they did list a forced regeneration after they replaced the sensor). So I don't understand how it could affect the low rev performance of the engine.

As long as it continues to work properly I guess I'm not going to lose too much sleep over it (and I now have a further 3 years of VW extended warranty to rely on).

[Preen59]

Interesting..

[4wheels]

What is it ? The yellow pictogram outline of an engine that stays lit up all the time (if it is continually flashing that indicates a different error).

What does it mean ? According to my owner's manual it means there is someting wrong with the "quality" of the exhaust gases.

Other symptoms ? On mine it ran really roughly just after starting once. It also seemed less torquey from 1,400 to 1,800rpm, at 1,800rpm it was a bit like a light switch had been flicked "ON" and away it went with normal power at those revs and higher. The DPF light (dots in a mffler diagram) did not light up at any time.

What was the fix ? My dealer replaced a faulty exhaust pressure sensor and forced a DPF regeneration (under warranty).

Did it fix it ? Seems to have (time will tell)

My engine is a late Nov 2006 build BPC 174hp 5 cyl R5 TDI with a DPF. It had done 53,000Km of mostly highway driving.


Has this happened to anyone else ?

Hi Greg,

That's what happened to mine (1/07 build 128Kw, 55,000Km) on my trip to Old Bar last October. Difference was it was Friday arvo on a long weekend, so the Newcastle dealer ran a fault check, but didn't want/have time to fix it. They (and VW Assist) advised it would be OK to continue gently, so I ended up going to Port Macquarie in 'limp mode' over a few days. There, they replaced the exhaust pressure sensor (G450), but found they couldn't regenerate the DPF (? because of 300Km of limp mode running) so that was replaced. Then they found the DPF sensor 'adrift' and (and wires burnt ? on hot DPF) so replaced that. Each of these items took an extra day, as they had to be ordered from Sydney. They also found the turbo intake pipe split (& replaced it). Not sure what the precipitating factor was. I suspect either the DPF sensor coming 'adrift' or the turbo intake pipe splitting, as it happened on one of the lovely crashing bumps you occasionally find at the northern end of the Newcastle freeway. The van did take a pounding on the Cape Yorke trip, but that was 15 months earlier. Maybe something was loose, just waiting for the straw to break the camels back.

All done under warranty, VW Assist came to the party with a hire car after some arm twisting, and I had some-where to stay, so 3 extra days in Port Macquarie was all it cost me. The bill to VW (which I got them to give me a copy of) was $2574.00, so that was incentive enough to get in early for the extended warranty, which, it turned out, was very timely, just before the price increase.

I've put another 3-4 1000Km on it now, and no sign of further problems.

Brian
2007 Trakkadu

[Transporter]

It’s hard to speculate, but when there is a fault in the engine management system (faulty exhaust pressure sensor) that could cause that DPF cannot regenerate then it is quite possible that ECM will reduce the power (will respond in the way it is programmed to respond) and also will let the driver know via the light (MIL) in the instrument panel.

But never trust the dealer. It’s a pity that you didn't get an independent VW shop to scan it with VCDS. You would know for sure if the dealer is telling the truth and what did they really replace.

Remember that you can also check the health of the DPF with VCDS.

[gregozedobe]

According to some of the guys over at the Brickyard forum there were a few faulty Exhaust pressure sensors on TDI engines, and yes, if it isn't working properly the ECU wouldn't be able to do a regeneration, thus possibly terminally clogging the DPF.

In my owner's manual it was quite explicit about only driving it direct to the dealer to be fixed when the "Exhaust gas warning lamp" stays on.

[petenkaz]

Hi, currently doing half a lap of oz with our Kombi Beach towing a Jayco camper. Quite a few hard miles over the last couple of months, and about at Woomera this light came on. As you say, reading the manual it says take it straight in to a dealer. I've booked into the VW dealer at Alice Springs for this Friday but still have a thousand or so k's before I get there. Anyone's thoughts on this delay? It is due for a service now and I was going to do oil and filters and save a big service for my return to brisbane. Be interested in hearing others thoughts on any potential long term damage / expense I may cause

[Sunny43.5]

This makes for an interesting read VW Diesel Particulate Filter issues | The Dog and Lemon Guide . But to be quite honest I did not think the 128kw T5 had a DPF had ours for 10 years and never seen any warnings or issues with it [have had the cool air intake hose shooting off problem but permanently fixed that one with a couple of screws ]This one from another site The exhaust emissions standards for new cars have effectively required fitment of a DPF in the exhaust of diesel cars since 2009 when the Euro 5 standard came into force.

[Transporter]

All T5 TDI have the DPF in AU since 7/2006.