Control system for exhaust light coming on?

[SeaGoat]

On two occsions over the past month or so, I have had an orange light stay on after I have started the engine (control system for exhaust). On the first occasion i switched off and tried again when the light remained lit. I switched off, consulted the manual (page 31, bottom of second column) and made a few phone calls. When I started the engine again the light went out.

 

The same thing happened again today.

 

What does this light mean?

[Ootohere]

Are you using 99 Ron. It will be best to if you are not. Was the car sitting ticking over for a while before this happened?. So how many miles has the car done and does it get a good chance of trips where it gets up to temp and a good blast?

Edited 19 October, 2014 by goneoffSKi

[xman]

The light is variously known as the MIL ( malfunction indicator light) emissions warning light, engine management fault light etc.

 

If it comes on, it indicates the ecu has detected a fault that could effect running and/or emissions, and the ecu may or may not change its mode of operation e.g. limp mode, depending on the fault.

 

It could be one of many faults, e.g. a misfire detected which might be plugs, coil, injector or others. It might be a sensor issue or many other possibilities.

 

Some faults are transient and clear themselselves, others may persist.

 

The only way to read the fault is to do a diagnostic with something like VCDS.

[SeaGoat]

Typically I use 97 RON, as it happens, I had 99 RON in the tank yesterday - I had used a Tesco "5p off" voucher a few days ago.

When I turned onthe ignition, the control system for exhaust light remained on, when I started the engine and when I started to drive the light remained on.

The car (VRS) has done about 8,000 miles.

I do a mix of local (city) and 60 to 300 mile mostly Motorway driving, I tend to exceed the speed limit only on rare occasions when overtaking

"Good blast"?

 

Some faults are transient and clear themselselves, others may persist.

 

The only way to read the fault is to do a diagnostic with something like VCDS.

 

I am ALWAYS nervous about unexplained transient faults!

Do the Skoda recovery people have access to VCDS Diagnostic gear or do I have to take the car into a dealer?

[Ootohere]

I would go to a dealer if the Light is not permanently on.

If it stays on, then try Skoda Assist, that way you get an Independent Opinion / Diagnosis before seeing a Skoda Technician.

Skoda Assist Responders should be able to read fault codes, but be sure they do not clear them.

 

With the vRS you can get EPC warning light show with misfires, or the 'Control System for  the Exhaust' warning. (your engine light)

or Both.

 

Unlikely to be a misfire due to the Spark Plugs at such a low mileage, & there are often not enough in a Cycle to log as a Fault Code.

But a Reading of the codes is as well to be done.

 

Since you changed fuels,

& also the Winter Spec Tesco Momentum had possibly been distributed in your area, be aware of the possiblity that this was the cause.

 

I have used 2 tanks of Winter Spec Momentum in the last week, and the car loves it,

But that is a CAVE with 38,000 miles and Stage 1.

 

george

Edited 20 October, 2014 by goneoffSKi

[newbie69]

Unfortunately this light can mean many different things like misfires or air leaks in the intake system so there is not a straightforward answer "it's that". It is only sensible to have it scanned either from you, the Skoda Assist, or a dealer. I have had it on during 3 different occasions and every time it was due to a different cause (leaking pipe in air induction / broken sensor clip / temporary misfire that didn't even register after new plugs not properly gapped to match stage 1.)

[tonyfvrs]

Mine comes on from time to time. Skoda assist told me to ignore it the first time; the third time I had the RAC out via Skoda assist and he found no faults recorded, but fiddled with a sensor connector and the light was out. Next time the car had not been driven for three weeks and the light came on when the engine was started; next day the light was out.

I recon if you can't feel a problem with the engine, ignore it. If it doesn't go out within a couple of days call Skoda assist or take to the dealer.

[Ootohere]

You must be aware not to push it with the EPC on or coming on occasionally, or the Exhaust Emission Control Light.

Or one then the other, or both show and stay on.

 

It can go into Limp Mode, 

and the Turbo can be 'Disabled' by the ECU to save damage being caused.

[pkoconnor]

Just read this one.

 

I have been away for 2.5 weeks and when I started the car and both EPC and exhaust emission control light came on and the revs fluctuated between 200 and 1500rpm.  Turned off the ignition left it a few seconds and turned it back on lights had gone off.  Been running a couple of days now and it's been ok.

 

2013 with 8000 miles on it... 

Edited 7 November, 2014 by pkoconnor

[SeaGoat]

Once again I had the "control system for exhaust" orange warning light stay on after I had started the engine.

This is the third time I have had this happen and it would not go out after I had switched off the engine, waited five minutes and startedup again.

I drove home (gently) and left the car parked up overnight.

Light still on this morning when I took the car for a short test drive.

I phoned the garage who agreed to have a look as soon as I could bring in the car.

One minute into the drive to the garage, the light went out.

The garage couldn't see any problems identified by the diagnostic computer although I think that there were a few logged reports of an air leak in the intake manifold?

They applied the latest Engine ECU patch and carried out another thorough check before telling me to get back to them immediately if I noticed anything odd and sending me on my way.

 

With the benefit of hindsight and checking my fuel bills I suspect that these three occurences coincided with occasions when I filled up with 99 RON fuel.

This is not to suggest that I believe there is anything wrong with 99 RON but it may be the case that the ECU detects an unexpected change and reports a fault.

I will stick religiously to 97 RON in future.

[Ootohere]

Whos 97 RON Super Unleaded do you buy. ?   & what 99 ron was it, Shell or Tesco?

(EDIT, i see from Post # 4 you had Tesco Momentum in.)

 

Because i know that Sainsbury Super unleaded caused the 'Exhaust Control System Light' to show when i was driving a Twincharger.

 

99 RON petrol put in, then no light shortly after.

 

No idea why you think that 97 should be OK & 99 ron not.

 

Even if your car has only done 8,000 miles,

there may be be misfires, just not logged.   'Not enough in a cycle to log'.

They maybe need to take out the 4 spark plugs and check them. since you are using 97 ron fuel.

?

or has that been part of the thorough checks they have done?

.............................

But the fact there are Codes for  'Air Leak in the intake manifold',  should tell the Technician something.

since others have required the 'Air Intake Manifold' replaced.

Edited 1 December, 2014 by goneoffSKi

[SeaGoat]

No idea why you think that 97 should be OK & 99 ron not.

 

This is not to suggest that I believe there is anything wrong with 99 RON but it may be the case that the ECU detects an unexpected change and reports a fault.

 

I somehow doubt that they removed and checked the plugs.

I suspect that the checks were to make sure that there was nothing amiss following the software update.

I know that when I got in the car and switched on, the front and rear wipers were switched on - and it wasn't raining.

[Ootohere]

So was that the extent of the checks to why the Exhaust Emission control light came on.

 

Look around the engine compartment, put it on VAS, do a ECU Update, check the electrics work.  Job Done.

 

Thats why so many go wrong, 

they are not keen to get the spanners out,  or get their gloves dirty,

whip out the plugs and see how they look.

[SeaGoat]

Had the "Control system for exhaust light" come on again.

Phoned the garage in a panic and because nobody from the service department was available I spoke to someone in Sales who said he would get someone from Service to call me back within 15 minutes.

Not having heard from them an hour later I called Skoda recovery. I still haven't heard back from the garage.

A VERY helpful, knowledgeable guy came out and within 15 minutes had identified and using VCDS and a laptop demonstrated a faulty sensor or faulty wiring.

The light has now gone off, so an intermittent fault which may suggest wiring?

Car booked in for rectification - different garage - here's hoping.