Engine Warning light on in MK2 FR TDi

[crmpicco]

I've got the Engine Warning light on in my MK2 FR TDi.

It came on about a month ago and then went off, but yesterday I drove 60 miles and then when I turned the car on to come home the light was on again.

I had the DPF sensor replaced last month, so I don't know if this is related.

It stays lit, rather than flashing which the manual says are two different faults.

Any idea what the problem is here?

 

[Joshkcupra]

Without plugging the car in to VAGCOM you won't know, either get obdii reader or take it to a garage and have the fault codes read. Otherwise its just a guessing game.

 

[crmpicco]

Would anyone be able to help me out with this problem?

I took the car to a local garage and they read the fault codes and said it wasn't specific about the problem based on the fault code reading. They suggested that I bring the car in for a DPF deep clean, which I did. This was on Monday and cost me a total of £300.

When I collected the car they told me not to be alarmed if the warning light came back on as they tried to get the sensor off to clean it/have a look at it, but it was stuck on. They said they tried heating it up, but couldn't get it off. Does this sound right? To me a sensor is normally plastic and involving electrical wiring. I'm familiar with heating up seized nuts to get the off...but that's normally metal.

So I find myself in the frustrating situation where I have spent £375 (300 on the DPF clean and 75 on a new sensor) and yet the light has returned today 6 days after the codes were reset and the deep clean was done. He mentioned that there were three sensor and they were really stuck on...

Can anyone advise if there's anything I can do to resolve this myself or if what the mechanic has told me sounds right?

Any help appreciated.

 

[mike0105]

Not sure, but having the codes might help. Did you make a note of them at all?

 

[Speed-FReek]

If there was a problem with the DPF then the yellow DPF light would have been on (directly above the centre of the needle) so I would be surprised a regeneration of the DPF was required. Either way, £300 for doing a regen sounds like daylight robbery.

Ask the garage for a printout of the fault codes. You've paid for them to do a fault diagnosis so you should be entitled to know what the fault codes were.

What sensors where they actually trying to replace? What they've told you about them not coming out and heating them up to try and do so doesn't sound right to me.

 

[crmpicco]

If there was a problem with the DPF then the yellow DPF light would have been on (directly above the centre of the needle) so I would be surprised a regeneration of the DPF was required. Either way, £300 for doing a regen sounds like daylight robbery.

Ask the garage for a printout of the fault codes. You've paid for them to do a fault diagnosis so you should be entitled to know what the fault codes were.

What sensors where they actually trying to replace? What they've told you about them not coming out and heating them up to try and do so doesn't sound right to me.

Thanks for the reply. Did you see the original post I posted up? Am I right in saying that is the engine management light?

Considering tomorrow will be a week since the DPF clean was done will they still have access to the fault codes if I were to ask for a print out? I don't want to pay to "go on the machine" again.

I don't think they were actually trying to replace the sensors I think they were just trying to give them a clean perhaps. He said there were three sensors and they were all stuck on. Are there three sensors attached to the DPF?

I've got a really bad feeling I've been screwed.

 

[crmpicco]

Not sure, but having the codes might help. Did you make a note of them at all?

No unfortunately I was never given any codes. The mechanic told me the machine read "unknown error".

 

[crmpicco]

Also does a DPF regen mean the same as a DPF deep clean?

 

[Speed-FReek]

Yes, there are 3 sensors around the DPF - two Exhaust Gas Temperature sensors (one before and one after the DPF), and a Lambda (oxygen) sensor. To be fair, if it was any of these three sensors they were trying to remove then using some heat to do so is viable because those sensors live their whole lives at some seriously hot temperatures and can handle that sort of heat abuse. The wires going into them are very well shielded so they can also cope with hot temperatures. There is also some Differential Pressure Sensors on the end of pipes that come off of the DPF (so not directly attached to the exhaust system / DPF) but the garage were probably talking about the former 3 sensors.

The light you have on is the "Emission Control System" (ECS) warning lamp. The ECS light and EML (Engine Management Light) are one and the same thing. There are a whole host of sensors that could cause that light to come on, not just the 3 sensors around the DPF that the garage were focusing on, so if they couldn't read the actual fault codes of the car because of an "unknown error" then they shouldn't have just started playing guessing games at your expense.

The term "deep clean" can only mean regeneration. They probably just said "deep clean" because they didn't want to baffle you with any technical jargon. However, with just the ECS light on and no DPF light, there was no need to do a regeneration of the DPF because there was no fault light indicating that actually needed to be done so they shouldn't have done that as part of their trial and error exercise at the price they were charging to do it.

I don't know where you're based but I would be inclined to try and find a friendly forum member nearby with VCDS and get them to do a fault code scan of your car. The garage are clearly trying to use some incompatible diagnostics software. I assume they're not a VAG dealer or independent VAG specialist? (I would certainly hope not based on your experience).