' Control system For Exhaust' Instrument warning light.

[4 wheel driver]

I partially stalled the engine on my 170 Diesel Yeti whist driving today, depressed the clutch, released it, the engine re-started and I drove on.

After a mile or two noticed that the , 'Control System For The Exhaust'  warning light was on.  I tried stopping, switching off and re-starting and the light stayed on.

The Handbook P34 says this light indicates a Re-gen issue with the DPF.  after the engine has tried to burn off the DPF accompanied by 2 warning lights and the words ' Diesel-Pariculate Owner's manual' being displayed if unsuccessful. None of this sequence happened. No limp home reduction in power or any other symptoms.  The only indication that there is a problem is the one solitary light on.

Can anyone offer advice? 

I have owned the 59 plate car from new, covered 30k almost exclusively on Shell regular and occasional V power and only been aware of a couple of re-gens over all that time so this event is puzzling!

Apologies for the details but I felt they would help in the analysis of the problem.

[gumdrop]

I would have panicked filled up with super diesel and done

a motorway run of some 50 miles each way, what I think is

called an "Italian reset"

[ejstubbs]

If you haven't had the DPF warning light or the "owner's manual" message then I would suspect that you don't have a DPF soot buildup problem (in which case the "Italian decoke" probably wouldn't achieve much beyond wasting fuel).

 

It sounds to me as if the system has detected a different but non-critical problem, especially since it hasn't put the engine in to limp mode.  It might be a sensor problem or something of that ilk - or the partial stall/self re-start might have put the system in to a confused state, or caused some other hiccup.  If it doesn't go away of its own accord fairly soon then I'd take it to a dealer/VAG service specialist and ask them to see whether a diagnostics check reveals anything.

[muddyboots]

Do you mean you effectively bump re-started it ?

 

Maybe some unburnt fuel passed through into the DPF, wouldn't have thought that would cause too much of an issue though.

 

Perhaps more to do with the unusual sequence of starting that it didn't like.

[4 wheel driver]

Thanks to 'ejstubbs' for your reply.

  I am thinking along the same lines...the coincidence of the 'stalling' and light coming on pretty much at the same time seem to indicate a  sensor prob. or something similar especially since no other DPF sequence of warning lights / regen / limp home where evident.

Has anyone else experienced similar issue?

Further suggestions welcome.

Thanks

[weasley]

Maybe an EGR issue?

[4 wheel driver]

DPF warning light    UPDATE:

Spoke to a Garage friend who looks after my car.  He plugged into a Diag. machine and it came up with, "Partial DPF blockage".

He drove it for about 25 mins. with the Diag. machine still plugged in to the car, returning with the light OUT.

I asked him why the correct sequence of Re-gen hadn't occured.  His explanation was that ECU's have a mind of their own and can do funny things.

His advice was to keep an eye on things and see how they go. He also recommended dropping into 5th on M'way / Trunk road occasionally to keep the DPF clear.

I will follow his advice , keep my fingers X'd. and report on the Forum of any further developments.

Thanks to those who responded to my Blog.

[DonjSZ5]

More likely your mate re-set the system. ECU's will reset after a battery disconnect/reconnect. I also suspect the 25 minute run was done at some high revs...sounds like you did not go with him.

[muddyboots]

I reckon it's unburnt fuel then, that got into the DPF and partially clogged it.

Decent run has cleared it.

[ejstubbs]

He also recommended dropping into 5th on M'way / Trunk road occasionally to keep the DPF clear.

 

You really shouldn't need to do that unless the DPF warning light comes on.  It's just wasting fuel otherwise.

[speedsport]

I reckon it's unburnt fuel then, that got into the DPF and partially clogged it.

Decent run has cleared it.

I tend to agree.

There's quite a difference between a soot build up in the DPF can and neat fuel getting into it. The re-gen cycle is designed to burn off dry soot particulates, not to deal with liquid fuel.

The cure could just have been a simple matter of your man getting some decently hot exhaust gasses through the system to clear any remaining liquid off whichever sensor triggered the warning.